CZ20002974A3 - 2- (purin-9-yl) -tetrahydrofuran-3,4-diol derivatives - Google Patents

Abstract

Compounds of general formula I, method of their preparation, pharmaceutical preparations and their use in the therapy of inflammatory diseases. Compounds of general formula I inhibit leukocyte activity and can therefore be used as immunosuppressive agents in autoimmune diseases, to inhibit metastasis or as a supportive agent in wound healing.

Description

Technical field

The invention relates to new chemical compounds, processes for their preparation, pharmaceutical preparations containing these compounds and their use in therapy.

State of the art

Inflammation is the primary response of the organism to tissue injury or to the entry of microbes into the organism, which is characterized by the adhesion of leukocytes to the endothelium, their penetration into the tissue by diapedesis and subsequent activation within the tissue. Leukocyte activation leads to the formation of toxic oxygen radicals (superoxide anion) and the release of granulation products (peroxidases and proteases). Circulating leukocytes are neutrophils, eosinophils and basophils, as well as monocytes and lymphocytes. Individual forms of the inflammatory reaction differ in the representation of infiltrating leukocytes, which is influenced by the degree of adhesion of tissue cells and the expression of cytokine and chemotactic factors of the tissue.

The primary function of leukocytes is to defend the host against invading organisms, or rather against bacteria and parasites. When a tissue is injured or infected, a complex chain reaction occurs that leads to local immigration of leukocytes from the circulation into infected tissues, to fully controlled and complete destruction and phagocytosis of foreign and dead cells, to subsequent tissue repair and breakdown of the inflammatory infiltrate. In chronic inflammatory conditions, immigration often occurs imperfectly, the breakdown of the inflammatory infiltrate is not adequately controlled, so that the inflammatory reaction causes tissue destruction.

In vitro and in vivo studies have shown that compounds acting on adenosine A2a receptors have anti-inflammatory effects (Cronstein, 1994). Studies of isolated neutrophil leukocytes have demonstrated inhibition of superoxide anion formation, degranulation, aggregation and adherence mediated by A2 receptors (Cronstein et al. 1983 and 1985, Burkey and Webster

- 1993, Richter 1992, Skubitz et al.-1988).

When using a substance selective for A2a receptors over A2b receptors (for example, CGS 21680), the extent of inhibition is identical to the activation of the A2a receptor (Diazani et al. - 1994).

Adenosine agonists probably also control other types of leukocytes (Elliot and Leonard 1989, Peachell et al. 1989). Animal studies have demonstrated an anti-inflammatory effect of methotrexate, which is mediated by adenosine and activation of A2 receptors (Asako et al. - 1993, Crostein et al. - 1993 and 1994).

Adenosine itself and compounds that increase adenosine levels demonstrate anti-inflammatory effects in vivo (Green et al.

- 1991, Rosengren et al. - 1995).

In humans, elevated plasma adenosine levels (caused by deaminase deficiency) lead to immunosuppression (Hirshom 1993).

We have discovered a new group of compounds with broad anti-inflammatory activity that inhibit leukocyte immigration from the circulation into the tissue and leukocyte activation within the tissue and have agonistic activity at the adenosine 2a receptor. The potential therapeutic effect of these compounds is the protective effect in diseases during which leukocyte-induced tissue destruction occurs. The compounds of the present invention are also safer in the treatment of inflammatory diseases

than treatment with corticosteroids, the use of which is limited by their serious side effects.

The compounds of the present invention exhibit superior effects to known A2a selective agonists due to their complete restriction of action on human A3 receptors. They even have antagonistic effects on human A3 receptors. A3 receptors have been observed on eosinophils and other cells of the inflammatory response (on mast cells) and activation of these receptors promotes the inflammatory response (Kohno et al. - 1996, Van Schaick et al. - 1996).

It is also considered that the bronchoconstrictive effects of adenosine in asthma may be mediated via A3 receptors (Kohno - 1996).

The essence of the invention

The invention consists of a compound of general formula I:

(i) where R ¹ and R ² independently represent the following groups:

1) C _3-8 cycloalkyl-;

2) hydrogen;

3) _aryl2CHCH2- ;

4) C _3-8 cycloalkyl-C _1-6 alkyl;

5) C1-4-alkyl;

6) aryl-C _1-6 alkyl-;

7) R4R5N-C1-6alkyl-;

8) _C1-6 alkyl-CH( _CH2OH )-;

9) aryl-C _1-5 alkyl-CH(CH ₂ OH)-;

10) aryl-C 1-5 alkyl-C(CH ₂ OH) ₂ -;

11) C ₃ -scycloalkyl- independently substituted with one, two or three -(CH ₂ ) _PR ⁶ groups;

12) H ₂ NC(=NH)NHC ₁ . ₆ alkyl-;

13) group formula

or a group in which one of the methylene carbon atoms adjacent to X (or both, if any) is replaced by methyl;

14) -C1-6alkyl-OH;

15) -C _1-8 haloalkyl;

16) group of the formula (CH ₂ ) _c CO(CH ₂ ) _d

NR

17) aryl

18) -(CH ₂ )fSO ₂ NHg(Ci-4alkyl-)2-g or

-(CH ₂ )fSO ₂ NHg(arylCi-4alkyl) ₂ - _g ;

R ³ denotes methyl, ethyl, -CH=CH ₂ , n-propyl, -CH ₂ CH=CH ₂ , CH=CHCH ₃ , isopropenyl, cyclopropyl, cyclopropenyl, -CH(OH)CH ₃ , -(CH ₂ ) _q halogen, -(CH ₂ ) _h Y(CH ₂ )iH, -COO(CH ₂ ),H, -CON(CH ₂ ) _m H((CH ₂ ) _n H), -CO(CH ₂ ) _o H or

C((CH ₂ ) _u H)=NO(CH ₂ ) _v H

Y represents O, S or N(CH ₂ ) j H;

a and b independently represent an integer from 0 to 4, where a+b is in the range from 3 to 5;

c, d and e independently denote an integer from 0 to 3, where c+d+e is in the interval from 2 to 3;

f denotes 2 or 3 and g denotes an integer from 0 to 2; p denotes 0 or 1; q denotes 1 or 2; h denotes 1 or 2;

i denotes an integer 0 or 1, so that h+i is in the interval from 1 to 2;

j denotes an integer from 0 to 2, where h+i+j is in the range from 1 to 2;

I indicates 1 or 2;

m and n independently represent an integer from 0 to 2, where m+n is in the interval from 0 to 2; o represents an integer from 0 to 2;

u and v independently denote 0 or 1, where u+v is an integer ranging from 0 to 1;

R ⁴ and R ⁵ independently represent hydrogen, C _1-6 alkyl, aryl, arylC 1-6 alkyl or NR ⁴ R ⁵ together represent pyridinyl, pyrrolidinyl, piperidinyl, morpholinyl, azetidinyl, azepinyl, piperazinyl or NC 1-6 alkyl-piperazinyl;

R ⁶ represents OH, NH 2 , NHCOCH 3 or halogen;

R ⁷ represents hydrogen, C _1-6 alkyl, -C 1-6 alkylaryl or -COC _1-6 alkyl;

X represents NR ⁷ , O, S, SO or SO ₂ ; and salts or solvates thereof.

C _x - _y alkyl refers to a saturated or unsaturated aliphatic carbon chain containing from x to y carbon atoms, which can form a straight or branched chain. The term alkoxy can be explained similarly, it mainly refers to saturated chains.

Aryl refers to mono- and bicyclic carboxylic aromatic hydrocarbons (phenyl, naphthyl) and heterocyclic aromatic hydrocarbons, which may contain, for example, 1-3 heteroatoms S, O and N (pyridinyl, pyrimidinyl, thiophenyl, imidazolyl, quinolinyl, furanyl, pyrrolyl, oxalyl). All of them may be optionally substituted (for example, with _C1-6 alkyl, halogen, hydroxy, nitro, C1-6 alkoxy, cyano, amino, SO2NH2 or _-CH2OH .

As C3-ecycloalkyl (used as radicals ^R1 and ^R2 ) we denote monocyclic alkyl groups (cyclopentyl, cyclohexyl) and bicyclic alkyl groups (norbornyl, for example exonorborn-2-yl).

An example of a (aryl) ₂ CHCH 2 - radical for R ¹ and R ² is Ph ₂ CHCH ₂ or a group in which one or two phenyl radicals are substituted by halogen or C 1-4 alkyl.

An example of C3-8cycloalkyl- _C1-6alkyl for ^R1 and ^R2 is ethylcyclohexyl.

Examples of C1-6alkyl for ^R1 and ^R2 are -( _CH2 ) _2C (Me)3, -CH(Et) ₂ and _CH2 = _C (Me) _CH2CH2- .

Examples of arylC1-6alkyl for ^R1 and ^R2 are -( _CH2 )2Ph, _-CH2Ph or this Ph can be replaced (one or more times) by halogen (iodine), amino, methoxy, hydroxy, _CH2OH or _SO2NH2 , -( _CH2 ) _{2 -} pyridinyl (i.e. -( _CH2 ) _2- pyridin-2yl, optionally substituted by amino), ( _CH2 ) _2imidazolyl (i.e. 1H-imidazol-4-yl) or such a group in which the imidazole is N-substituted by C1-6alkyl (especially methyl).

Examples of R ⁴ R ⁵ N-C 1-6 alkyl for R ¹ and R ² are ethyl-piperidin-1-yl, ethyl-pyrrolidin-1-yl, ethyl-morpholin-1-yl, -(CH ₂ ) 2 NH(pyridin-2-yl) and -(CH ₂ ) ₂ NH ₂ .

An example of a _C1-6 alkyl-CH( _CH2OH )- radical for ^R1 and ^R2 is _Me2CHCH ( _CH2OH )-.

An example of an _arylC1-5 alkyl-CH( _CH2OH )- radical for ^R1 and ^R2 is especially _PhCH2CH ( _CH2OH )-.

An example of arylC1-5alkyl-C( _CH2OH ) _2- for ^R1 and ^R2 is _PhCH2C ( _CH2OH ) _2- .

An example of a C3-8cycloalkyl- radical independently substituted with one or more ~( _CH2 ) _PR6 ^groups (i.e. 1, 2 or 3 such groups) for ^R1 and ^R2 is 2-hydroxy-cyclopentyl (especially trans-2-hydroxy-cyclopentyl) and 4-amino-cyclohexyl (especially trans-4-amino-cyclohexyl).

An example of H ₂ NC(=NH)NHC _1-6 alkyl for R ¹ and R ² is H ₂ NC(=NH)NH(CH ₂ ) ₂ -.

An example of groups of general formula

X (CH/

for R ¹ and R ² is pyrrolidin-3-yl, piperidin-3-yl, piperidin-4-yl, tetrahydro-1,1-dioxide, thiophen-3-yl, tetrahydropyran-4-yl, tetrahydro-thiopyran-4-yl and 1,1-dioxo-hexahydro-1.lambda.6thiopyran-4-yl, or a derivative N-substituted with C 1-6 alkyl (for example methyl), C _1-6 alkylacyl (for example acetyl), arylC 1-6 alkyl (for example benzyl).

Examples of _C1-6 alkyl-OH for ^R1 and ^R2 _{are -CH2CH2OH} and -CH( _CH2OH )CH( _CH3 ) ₂ .

Examples of C1-6-haloalkyl for ^R1 and ^R2 _{are -CH2CH2CI} and ( _CH3 ) _2CIC ( _CH2 ) _3- .

Examples of groups of the general formula (( _CH2 ) _cCO < _CH2 ), ^.NR7 '( _ch2v ) for ^R1 and ^R2 are 2-oxopyrrolidin-4-yl, 2-oxopyrrolidin-3-yl or a derivative N-substituted with C1-6alkyl (for example methyl) or benzyl.

An example of aryl for R ¹ and R ² is phenyl optionally substituted with halogen (e.g. fluorine, especially 4-fluoro).

An example of a -(CH ₂ ) f SO ₂ NH ₉ (C 1-4 alkyl) ₂ -g group for R ¹ and R ² is -(CH ₂ ) ₂ SO ₂ NHMe, and an example of a -(CH ₂ ) _f SO ₂ NH 9 (arylC 1-4 alkyl) ₂ .g group for R 1 and R 2 is -(CH ₂ ) 2 SO ₂ NHCH ₂ Ph.

An example of a C1-6alkyl residue for ^R7 is methyl, an example of a C1-6alkyl-aryl residue for ^R7 is benzyl, and an example of _-COC1-6alkyl for ^R7 is acetyl.

We prefer that R ¹ and R ² are not both hydrogen.

We prefer that the radical R ¹ is aryl ₂ CHCH ₂ -.

We further prefer that R ¹ represents _{C 1-6 alkyl, C 3-8 cycloalkylC 1-6 alkyl ,} arylC _1-6 alkyl or hydrogen.

We prefer that ^R2 denotes -CH( _CH2OH ) _C1-3 alkyl, 4-aminocyclohexyl, pyrrolidinyl (especially pyrrolidin-3-yl) or _arylCH2CH2- , especially where aryl denotes (1-C1-3 alkyl-1Himidazol- ₄ -yl).

We further prefer that ^R2 denotes: pyrrolidin-3-yl, in which it is N-substituted with C1-6alkyl or benzyl, further ^{R4 R5} _NC1-6alkyl ,

_C1.6 alkyl-OH, ·· • · aryl (especially where aryl denotes phenyl substituted by halogen), aryl- _{C1.5 alkyl} -CH( _CH2OH )-,

C ₃ . ₈ cycloalkyl, aryl(CH ₂ ) 2 (especially where aryl denotes pyridinyl (especially pyridin-2-yl), 1H-imidazol-4-yl, phenyl or phenyl disubstituted with methoxy) or

_{C 3-8 cycloalkyl} independently substituted with one or more (i.e. 1, 2 or 3) (CH ₂ ) _PR® groups.

We prefer that R ³ denotes methyl, ethyl, n-propyl, cyclopropyl, -CH ₂ OH -COOCH ₃ or -CH=NOH, especially methyl, ethyl, n-propyl, cyclopropyl or -CH ₂ OH.

We particularly prefer that R ³ represents methyl, ethyl, n-propyl or cyclopropyl, especially methyl, ethyl or cyclopropyl, most preferably methyl or ethyl, most preferably ethyl.

We prefer that R ⁴ and R ⁵ independently represent hydrogen, C 1-6 alkyl, aryl, arylC 1-6 alkyl- or NR ⁴ R ⁵ together represent pyrrolidinyl, piperidinyl, morpholinyl, azetidinyl, azepinyl, piperazinyl or N-C 1-8 alkyl-piperazinyl.

We particularly prefer that R ⁴ and R ⁵ independently denote hydrogen or aryl or NR ⁴ R ⁵ together denote pyrrolidinyl, piperidinyl, morpholinyl, azetidinyl, azepinyl, piperazinyl or N-methyl-piperazinyl.

We prefer when p denotes 0.

We prefer that R ⁶ represents OH or NH ₂ .

We prefer when q denotes 1.

We prefer when h denotes 1.

We prefer when i denotes 0.

We prefer when j denotes 1.

• · · · · · ς ;

............ .· «ί·

We prefer when I indicates 1.

We prefer when man indicates 0.

We prefer when o denotes 1.

We prefer when u denotes 0.

We prefer when v denotes 0.

We prefer when Y denotes O.

We prefer when a denotes 2, and when b denotes 1 or 2.

We prefer that X represents NR ⁷ (for example NH), O, S or S0 ₂ , especially O, S or NH.

We prefer when c denotes 0, and when either d denotes 1 and e denotes 1 or d denotes 0 and e denotes 2. ,

We prefer that R ⁷ represents hydrogen.

We particularly prefer that R ¹ represents Ph 2 CHCH 2 - We particularly prefer that R ¹ represents CH(CH 2 CH 3 ) 2 , phenylethyl, cyclohexylethyl, -(CH ₂ ) 2 C(CH ₃ ) 3 or hydrogen.

We particularly prefer when R ² denotes CH(CH ₂ OH)CH(CH ₃ ) ₂ (especially 1S-hydroxymethyl-2-methylpropyl), trans-4-amino-cyclohexyl, 2-(1-methyl-1H-imidazol-4yl)CH ₂ CH ₂ - or pyrrolidin-3-yl.

We particularly prefer when R ² denotes 2-(1H-imidazol-4-yl)ethyl, morpholin-1-yl-ethyl, pyrrolidin-1-yl-ethyl, pyridin-2-yl-amino-ethyl, (+)-exonorborn-2-yl, 3,4-dimethoxy-phenylethyl, 2-hydroxy-ethyl, 4fluoro-phenyl, N-benzyl-pyrrolidin-3-yl, pyridin-2-yl-ethyl, 1S-hydroxymethyl-2-phenyl-ethyl, cyclopentyl, phenylethyl, piperidin-1-yl-ethyl or 2-hydroxy-pentyl (especially trans-2-hydroxy-pentyl).

* ·· *« · * · · • 9999 99

It is most suitable when R ¹ denotes Ph ₂ CHCH ₂ -, CH(CH ₂ CH ₃ ) ₂ , hydrogen or phenylethyl-.

Most preferably, R ² represents 2-(1-methyl-1H-imidazol-4yl)-CH ₂ CH ₂ -, 1S-hydroxymethyl-2-phenylethyl, phenylethyl or 1S-hydroxymethyl-2-methylpropyl.

The most preferred compounds of general formula I are:

(2R,3R,4S,5S)-2-{6-(2,2-diphenyl-ethylamino)-2-[2-(1-methyl-1 Himidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-ethyl-[1,2,4]oxadiazol-5yl)-tetrahydro-furan-3,4-diol;

(2S,3S,4R,5R)-2-(3-ethyl-[1,2,4]oxadiazol-5-yl)-5-{6-(1-ethylpropyl-amino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin9-yl}-tetrahydro-furan-3,4-diol;

(2R,3R,4S,5S)-2-{6-(1-ethyl-propylamino)-2-[2-(1-methyl-1-Himidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol;

(2R,3R,4S,5S)-2-{6-(2,2-diphenyl-ethylamino)-2-[2-(1-methyl-1-Himidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-methyl-[1,2,4-yoxadiazol-5-yl)-tetrahydro-furan-3,4-diol;

(2R,3R,4S,5S)-2-{6-amino-2-[2-(1-methyl-1H-imidazol-4-yl)ethylamino]-purin-9-yl}-5-(3-methyl-[1,2,4loxadiazol-5-yl)tetrahydrofuran-3,4-diol;

(2R,3R,4S,5S)-2-[6-amino-2-(1S-hydroxy-methyl-2-phenylethylamino)-purin-9-yl]-5-(3-methyl-[1,2,4j-oxadiazol-5-yl)tetrahydrofuran-3,4-diol;

(2R,3R,4S,5S)-2-(6-Amino-2-phenethyl-amino-purin-9-yl)-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol;

(2S,3S,4R,5R)-2-(3-cyclopropyl-[1,2,4]oxadiazol-5-yl)-5-[6-(1-ethyl-propyl-amino)-2-(2-(1-methyl-1H-imidazol-4-yl)-ethylamino)purin-9-yl]-tetrahydrofuran-3,4-diol;

A AA • A A A A • A • A A A A A A A A • A A A A A A A AAAA A A A A A A A A A A A A A AAA A A •A A A A A A A A

(2R,3R,4S,5S)-2-{6-phenethylamino-2-[2-(1-methyl-1H-imidazol-4yl!)-ethyl-amino]-purin-9-yl}-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)tetrahydrofuran-3,4-diol;

(2R,3R,4S,5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(1S-hydroxymethyl-2-methyl-propyl-amino)-purin-9-yl]-5-(3-ethyl[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol;

(2R,3R,4S,5S)-2-[6-(1-Ethyl-propyl-amino)-2-(1S-hydroxymethyl-2-phenyl-ethyl-amino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)tetrahydrofuran-3,4-diol;

and its salts and solvates.

The stereochemical properties of the compounds are included in the general formula I. If the side chains contain chiral centers, then the invention also relates to mixtures of enantiomers (including racemic mixtures), diastereoisomers and individual enantiomers. It is generally preferred to use the compound of general formula I in the form of a purified single enantiomer.

The invention relates to the first part of the preparation of compounds of general formula I, including the reaction of a compound of general formula II:

* ·· · , where L denotes a leaving group - halogen (especially chlorine), or a derivative thereof with a bonded protecting group, with a compound of formula R ² NH2 or a derivative thereof with a bonded protecting group.

In this reaction, the reagents are heated to a temperature of 50-150°C in the presence of an inert solvent (DMSO). The compound of general formula II can be used in the form of a derivative with a bond of protective groups (acetonide or acetyl groups) on two hydroxyl groups. Compounds of general formula R ² NH2 are known or can be prepared by generally known procedures.

Compounds of general formula II can be prepared from compounds of general formula IV. First, the carboxyl group of the compound of general formula IV is activated, followed by the reaction of the amidoxime of formula OH-N=C(R ³ )NH2 in a solvent (tetrahydrofuran), and then cyclization in a solvent (toluene) at a temperature of 20-150°C.

Carboxylic activation is the reaction of an acid chloride (pivalolyl chloride) or an acid anhydride in the presence of a base (tertiary amine - diisopropylethylamine). Activating agents used in peptide chemistry (EEDQ) can be used. Hydroxyl groups can be removed by generally valid procedures, for example, acetonide can be removed by the action of an aqueous acid solution (trifluoroacetic or acetic acid at a temperature of 0-150°C.

• 4

Scheme of a suitable procedure for the first part of the preparation: Scheme 1

TFA/water

0°C to room temperature

A suitable leaving group L is halogen (especially chlorine).

The use of the isopropylidine protecting group of the two hydroxy groups of ribose in compounds of general formula III and IV is not limiting; other protecting groups may also be used.

Compounds of general formula IV can be prepared according to preparation procedure 4 (R ¹ = Ph ₂ CHCH ₂ -) disclosed in International Patent Application WO 94/17090 or by a similar procedure.

4 * 9999

4

The synthesis of amidoximes is described by Flora et al. - 1978 and Bedford et al. - 1986.

Compounds of general formula II can also be prepared according to a process in which a compound of general formula (V) enters the reaction:

where L ¹ and L ² independently denote a leaving group (halogen, i.e. chlorine) or their derivatives with a protective group bond, with a compound of the general formula R ¹ NH2. The reaction is preferably carried out in the presence of a base (amine diisopropylethylamine) in a solvent (alcohol - isopropanol) at an elevated temperature (50°C).

The invention relates to the second part of the process for preparing compounds of general formula I, where the compound of general formula VI:

OH

HO OH (VI) or its derivative with a protective group bond reacts with a carboxyl sensor (EEDQ) and an amidoxime of the general formula OH-N=C(R ³ )NH2. It is convenient if the reaction takes place at a temperature of 50°-150°C and in the presence of an inert solvent (dioxane).

The compound of general formula VI can be prepared by oxidation of the hydroxymethyl group of the compound of general formula VII. A suitable oxidation method is the reaction of the compound of general formula VII with permanganate (potassium permanganate) in the presence of a base (aqueous potassium hydroxide solution) and a water-miscible solvent (dioxane) at a temperature of 0°C-50°C. Another suitable oxidation method is the use of TEMPO in the presence of hypochlorite (sodium hypochlorite) and a metal bromide (potassium bromide), in the presence of a base (sodium bicarbonate) in a biphasic aqueous solvent (ethyl acetate) and water at a temperature of 0°-50°C.

Diagram of the appropriate procedure for the second part of the preparation:

DMSO, 90* C

FvNH,

HIM

CH

NHR ^:

NHR (Vlil) (VII)

• 9

(1)

1. EEDQ DICXAř, 2

103*C. fyOH from

N

NH,

2. TFA/water O*C

where L denotes a leaving group such as halogen, especially chlorine.

Compounds of general formula (VII) can be prepared by reacting compounds of general formula VIII with an amine of general formula R ² NH2 in an inert solvent (DMSO) at a temperature of 50-150° C. Commercially available amines of general formula R ² NH2 can be used or they can be prepared by generally known methods.

Compounds of general formula VIII are prepared according to the procedure described in Preparation 3 (R ¹ = Ph ₂ CHCH ₂ -) in International Patent Application WO 94/17090.

The invention relates to the third part of the preparation of the compound of general formula I, where the compound of general formula IX enters the reaction:

• » and a compound of general formula X:

(X) where L is a leaving group or derivatives thereof with a protective group attachment.

The compound of general formula X is suitable for use in the form of a derivative, where the hydroxyl groups in the 2- and 3- ribose positions have a bonded protecting group (e.g. acetyl). The hydroxyl group OH can be chosen as the leaving group L, but especially Crealkoxy (methoxy or ethoxy groups), an ester residue (acetyloxy - or benzyloxy-) or halogen. The preferred group L- is acetyloxy-. The reaction mixture is formed by combining the reactants in an inert solvent (methyl cyanide) in the presence of a Lewis acid (TMSOTf) and DBU.

This procedure is suitable for the preparation of compounds of general formula II, where a derivative of the compound of general formula IX with the L group attached instead of R ² NH is used. The same procedure is suitable for the preparation of compounds of general formula V.

Compounds of general formula IX (and the above-mentioned derivatives) can be prepared by generally known methods.

»·· ···· ** ·»· ·· ·

Compounds of general formula VIII can be prepared according to Scheme 3:

Scheme 3

POCl 3 , N,N-dimethylaniline, MeCN, reflux

(IX) ( ^xl )

Compounds of general formula X can be prepared according to the procedure for preparing compounds of general formula III.

The invention relates to the fourth part of the preparation of compounds of general formula I, where the compound of general formula IIa is introduced into the reaction

HO where L denotes a leaving group (chlorine), or a derivative thereof with a protective group bond to a compound of formula R ¹ NH ₂ according to the procedure above.

Compounds of general formula IIa can be prepared by reacting a compound of formula (XI) ¹

N

N

H (XI) ¹ (L denotes primarily halogen, i.e. chlorine) with a compound of general formula X according to the procedure of the third part of the synthesis.

Compounds of general formula (XI) ¹ can be prepared according to the procedure of Scheme 3 or in an analogous manner.

The invention relates to a fifth part of the preparation of compounds of general formula I, in which R ¹ denotes hydrogen. In this part, the compound of general formula IIb is converted

for example, by the action of PPh ₃ , and subsequently by water.

Compounds of general formula IIb can be prepared by reacting a compound of general formula Va

with a compound of the general formula R ² NH ₂ according to the procedure of the first part of the synthesis.

Compounds of general formula Va can be prepared by reacting a compound of general formula V, where L ¹ and L ² independently denote a leaving group (halogen, i.e. chlorine), or a protected derivative thereof, with a compound of general formula NaN ₃ .

The invention relates to a sixth part of the preparation of compounds of general formula I, in which the protecting groups of the compound of general formula I are removed and this compound or its salt is converted into another salt, if necessary.

Compounds of the general formula R ¹ NH2, R ² NH2 and OHN=C(R ³ )NH ₂ are commercially available or can be prepared by generally known methods.

The protecting groups mentioned in this patent application and the means for their removal are described in the publication T.W.Green "Protective Group in Organic Synthesis" (J.Wiley and Sons, 1991).

Suitable hydroxyl protecting groups are alkyl (methyl), acetate (acetonide) and acyl (acetyl or benzoyl), which can be removed by hydrolysis or arylalkyl (benzyl), which can be removed by catalytic hydrogenolysis. Suitable amino protecting groups are sulfonyl (tosyl), acyl (benzyloxycarbonyl or t-butoxycarbonyl) and arylalkyl (benzyl), which can be removed by hydrolysis or hydrogenolysis.

Suitable salts of the compounds of general formula I are physiologically acceptable salts, such as acid addition salts derived from inorganic or organic acids (hydrochlorides, hydrobromides, sulfates, phosphates, acetates, benzoates, citrates, succinates, lactates, tartrates, fumarates, maleates, 1-hydroxy-2-naphthoates, methanesulfonates and optionally their inorganic basic salts (alkaline earth salts - sodium salts). Other salts of the compounds of general formula I, including salts that are physiologically unacceptable, can be used to prepare the compounds of general formula I and their physiologically acceptable salts. Such salts include trifluoroacetates and formates.

Suitable solvates of compounds of formula I include hydrates.

Acid addition salts of compounds of general formula I are obtained from free bases of general formula I, which are treated with the corresponding acid.

Compounds of formula I inhibit leukocyte activity, as demonstrated by their ability to inhibit superoxide (O ₂ ') formation in chemically stimulated neutrophils (N-formyl-methionyl-leucyl-phenylalanine - fMLP). It follows that compounds of formula I have a potential therapeutic effect by protecting against leukocyte-induced tissue damage.

Diseases in which a potential anti-inflammatory effect can be applied include;

respiratory diseases - adult respiratory distress syndrome (ARDS), bronchitis (including chronic bronchitis), cystic fibrosis, asthma (including allergen-induced asthmatic reactions), emphysema, rhinitis and septic shock;

gastrointestinal diseases - inflammatory bowel diseases (Crohn's disease or ulcerative colitis), gastritis caused by Helicobacter pylori, radiation or allergen-induced secondary inflammatory diseases or gastropathy caused by nonsteroidal anti-inflammatory drugs;

skin diseases - psoriasis, allergic dermatitis and hypersensitivity reactions and CNS diseases - Alzheimer's disease and multiple sclerosis.

• · • ·

Diseases in which the potential therapeutic effect of the compounds of the present invention can be applied include:

heart disease - peripheral vascular disease, postischemic reperfusion injury and idiopathic eosinophilic syndrome.

The compounds of the present invention inhibit the function of lymphocytes and can be used as immunosuppressive agents in autoimmune diseases (rheumatic arthritis and diabetes).

The compounds of the present invention can be used to inhibit metastasis or as a wound healing aid.

The invention relates not only to the treatment of advanced diseases, but also to their prophylaxis.

Compounds of general formula I can be used in the treatment of humans and animals, especially as substances with anti-inflammatory effect.

The invention relates to a compound of general formula I or a pharmaceutically acceptable salt or solvate thereof useful in the treatment of humans or animals, in particular in the treatment of inflammatory diseases which lead to tissue damage.

The invention also relates to the use of a compound of general formula I or a physiologically acceptable salt or solvate thereof in the preparation of a medicament for the treatment of inflammatory diseases in patients susceptible to leukocyte-induced tissue damage.

The invention relates to a method of treating humans and animals with inflammatory diseases susceptible to leukocyte-mediated tissue damage, which comprises administering to the human or animal an effective amount of a compound of general formula I or a salt or solvate thereof.

The compounds of the present invention may be administered in any suitable form. The invention relates to any pharmaceutical composition for the treatment of inflammation which comprises a compound of formula I or a pharmaceutically acceptable salt or solvate thereof, optionally together with one or more pharmaceutically acceptable carriers and excipients.

The invention relates to the preparation of pharmaceutical compositions containing multiple components.

The compounds of the present invention can be formulated for oral, buccal, parenteral, topical or rectal administration, particularly parenteral or topical (aerosol) administration.

Tablets and capsules for oral administration may contain: appropriate excipients - syrup, acacia gum, gelatin, sorbitol, tragacanth, starch, cellulose or polyvinylpyrrolidone; fillers - lactose, microcrystalline cellulose, sugar, corn starch, calcium phosphate or sorbitol;

lubricants - magnesium stearate, stearic acid, talc, polyethylene glycol or silicon dioxide;

disintegrating agents - potato starch, croscarmellose sodium or sodium starch glycolate; wetting agents - sodium lauryl sulfate.

The tablets can be coated according to generally known procedures.

Liquid oral preparations may be prepared as an aqueous or oily suspension, solution, emulsion, syrup or elixir, or as a dry product for reconstitution with water or other suitable vehicle before administration. Suitable additives for such preparations are:

suspending agents - sorbitol syrup, methylcellulose, glucose/sugar syrup, gelatin, hydroxymethylcellulose, carboxymethylcellulose, aluminum stearate gel or • · • · · ·· · • · · · · ♦ » · · hydrogenated edible fats;

emulsifying agents - lecithin, sorbitan mono-oleate or acacia gum;

anhydrous carriers ( ^such as oils) - almond oil, fractionated coconut oil, oily esters, propylene glycol or ethyl alcohol; preservatives - methyl or propyl p-hydroxybenzoates or sorbic acid.

The preparations may optionally contain buffer salts, flavoring and coloring agents and/or sweeteners (mannitol).

For buccal administration, tablets in the form of tablets or lozenges prepared by conventional methods can be used.

The compounds may be administered in the form of suppositories, which may be prepared using suitable suppository bases - cocoa butter or other glycerides.

The compounds of the present invention may be administered parenterally by injection or continuous infusion. The formulations may be formulated in unit dose forms such as ampoules, vials, small volume infusion containers or pre-filled syringes or in storage containers containing a larger number of unit doses together with added preservatives. The formulations may be used in the form of a solution, suspension or emulsion in an aqueous or non-aqueous vehicle which may contain excipients such as antioxidants, buffers, antimicrobials and/or tonicity agents. The active ingredient may be prepared in powder form which is mixed with a suitable vehicle, i.e. sterile, pyrogen-free water, prior to use. The formulation in solid dry form is prepared by filling into individual sterile storage containers or by aseptically filling a sterile solution into individual storage containers and then lyophilizing them.

Local routes of administration include inhalation and insufflation. Topical preparations include ointments, creams, lotions,

powders, pessaries, sprays, aerosols, capsules or inhaler or insufflator cartridges, nebulization solutions or drops (eye drops or nose drops).

Ointments and creams may contain an aqueous or oily base together with suitable thickening agents and/or gelling agents and/or solvents. These bases include water and/or an oil (liquid paraffin) or a vegetable oil (peanut oil or castor oil) or a solvent (polyethylene glycol). Soft paraffin, aluminum stearate, cetostearyl alcohol, polyethylene glycols, microcrystalline wax and beeswax may be used as thickening agents.

Lotions can be prepared from aqueous or oily bases and generally also contain one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents, or thickening agents.

Powders for external use may be prepared with the aid of other suitable powder bases (talc, lactose or starch). Drops may be prepared from aqueous or anhydrous bases together with one or more dispersing agents, solubilizing agents or suspending agents.

Preparations as sprays can be prepared using aqueous solutions or suspensions or as aerosols, which are applied from pressurized containers using suitable propellants (dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1,2tetrafluoroethane, carbon dioxide or other suitable gases.

Intranasal sprays can be prepared from aqueous or anhydrous carriers with the addition of thickening agents, buffer salts or acids or alkalis to adjust the pH, agents ensuring the isotonicity of the preparation, and antioxidants.

Capsules and cartridges (e.g. gelatin) or blisters (e.g. laminated aluminum foil) for use in inhalers or insufflators may contain a powder containing a compound of the present invention and a suitable powder base (lactose or starch).

Solutions for nebulization may be prepared in an aqueous carrier with the addition of agents such as acids or bases, buffer salts, isotonicity agents, and antimicrobials. The preparations may be sterilized by filtration or autoclaving, or may be prepared as a non-sterile product.

The pharmaceutical compositions of the present invention can be used in combination with other drugs, for example with:

anti-inflammatory drugs - corticosteroids (fluticasone propionate, beclometasone dipropionate, mometasone furoate, triamcinolone acetonide or budesonide) or NSAIDs (sodium cromoglycate);

beta-adrenergic drugs - salmeterol, salbutamol, formoterol or terbutaline and their salts;

antibacterial or antiviral drugs.

The invention relates to a pharmaceutical preparation which comprises a compound of general formula I or a physiologically acceptable salt or solvate thereof together with another drug, for example with anti-inflammatory drugs (corticosteroids or NSAIDs).

The invention relates to the above-mentioned combination of drugs in the form of a pharmaceutical preparation containing the above-mentioned combination of drugs with pharmaceutically acceptable carriers.

The individual components of such combinations may be administered sequentially or simultaneously in the form of separate or combined pharmaceutical preparations. The appropriate doses of known drugs are determined according to generally accepted rules.

The compounds of the present invention may be administered in a dose of from 0.01 to 500 mg/kg body weight, in particular from 0.01 to 100 mg/kg body weight, one to four times daily. The exact determination of the individual dose depends on the age, the stage of the disease of the patient and the chosen route of administration.

Some of the described intermediate compounds are novel and are part of the present invention.

The advantages of the compounds of the present invention are their higher efficacy, higher selectivity, fewer side effects, longer duration of action, higher bioavailability when choosing the preferred route of administration, and less systemically available when administered by inhalation or have more known desirable properties than similar known compounds.

The compounds of the present invention are advantageous primarily for their selectivity for adenosine 2a receptors, which is higher than for other adenosine receptors (especially for A1 and A3 receptors) compared to previously known compounds.

• · 9

The biological activity of the compounds of the present invention can be demonstrated by in vitro and in vivo tests according to the following methods:

1/ Agonistic action on adenosine receptors type 2a and 3

The agonistic selective action of the compound of the present invention on adenosine receptors can be monitored in Chinese hamster ovary (CHO) cells transfected with the gene for the corresponding human adenosine receptor, and subsequently processed by the following method according to Castanon and Spevak, 1994. The gene for secreted placenta alkaline phosphatase (SPAP), the activity of which is influenced by the presence of cAMP response components (Wood, 1995), is also transferred into CHO cells. The efficacy of the compounds under investigation is determined by their effect on basal levels of cAMP (A2a) or on forskolin-enhanced levels of cAMP (A1 and A3), which is manifested by a change in SPAP levels. The EC50 value is determined relative to the non-selective agonist N-ethyl-carboxamide-adenosine (NECA).

2/ Antigen-induced accumulation of pulmonary eosinophils in sensitized guinea pigs

Ovalbumin-sensitized guinea pigs are given 1 mg/kg intraperitoneally of mepyramine as a protective dose to prevent the development of anaphylactic bronchospasm. The compound of the present invention is administered by inhalation (30 minutes of inhalation of an aerosol of the compound of the present invention), followed immediately by inhalation of ovalbumin (30 inhalations of an aerosol prepared from a 50 pg/ml solution of albumin). 24 hours after ovalbumin administration, the guinea pigs are sacrificed and the lungs are lavaged. The total and

differential leukocyte count, and then the dose of the test compound causing a 50% reduction in eosinophilic leukocyte accumulation (ED ₅₀ ) is determined (Sanjar et al. 1992).

• 4 · • · · · ♦ 4 4 4 4 ♦ 44 4444 44 444

4 4 «44

Literature:

Asako H, Wolf RE, Granger DN (1993), Gastroenterology 104, pp. 31-37;

Bedford CD, Howd RA, Dailey OD, Miller A, Nolen HW III, Kenley RA, Kern JR, Winterle JS, (1986), J. Med. Chem: 29, pp. 2174-2183;

Burkey TH Webster RO, (1993), Biochem. Biophys. Acta 1175, pp. 312-318;

Castanon MJ, Spevak W, (1994), Biochem. Biophys Res. Commun, 198, pp. 626-631;

Cronstein BN Kramer SB, Weissmann G, Hirschhorn R, (1983), Trans. Assoc. Am. Physicians 96, pp. 384-91;

Cronstein BN Kramer SB, Rosenstein ED, Weissmann G, Hirschhorn R, (1985), Ann NY. Acad. Sci. 4S1, pp. 291-301;

Cronstein BN Naime D, Ostad E (1993), J. Clin. Invest. 92, pp. 2675-82;

Cronstein BN Naime D, Ostad E, (1994), Adv. Exp. Copper. Biol, 370, pp. 411-6;

Cronstein BN (1994), J. Appl. Physiol. 76, pp. 5-13;

Dianzani C Brunelleschi S, Viano I, Fantozzi R, (1994), Eur. J. Pharmacol 263, pp. 223-226;

Eillot KRF, Leonard EJ, (1989), FEBS Letters 254, pp. 94-98;

Flora KP, van't Riet B, Wampler GL, (1978), Cancer Research, 38, pp. 1291-1295;

Green PG, Basbaum Al, Helms C Levine JD, (1991), Proc. Natl. Acad Sci. 88, pp. 4162-4165;

Hirschorn R, (1993), Pediatr. Res 33, pp S35-41;

Stove Y; Xiao-duo J; Mawhorter SD; Koshiba M; Jacobson KA.

*A · A A • · AA AAA • A A A A

A AAAA

A A · AAA ·· AAA AA AAA (1996). Blood 88 pp. 3569-3574.

Peachell PT, Lichtenstein LM, Schieimer RP, (1989), Biochem Pharmacol 38, pp. 1717-1725;

Richter J, (1992), J. Leukocyte Biol. 51, pp. 270-275;

Rosengren S, Bong GW, Firestein GS, (1995), J. Immunol. 154, pp. 5444-54S1;

Sanjar S, McCabe PJ, Fattah D, Humbies AA, Pol SM, (1992), Am. Roar.

Respir. Dis, 14S, A40;

Skubitz KM, Wickman NW, Hammerschmidt DE, (1988), Blood 72, pp. 29-33

Van Schaick EA; Jacobson KA; Kim HO; Ijzerman AP; Danhof

M. (1996) Eur J Pharmacol 308, pp. 311-314.

Wood KV. (1995) Curr Opinion Biotechnology 6 pp. 50-58.

♦ »♦ ♦· · ·· · · · · ·· • ♦ * φ · • · · · · φ • · · * · ··· ···* ·· >·«

Examples of embodiments of the invention

Clarification of the terms used:

If purification by flash column chromatography is specified, it is a silica gel column with a pore size of 0.040 to 0.063 mm mesh (i.e. Merck Art 9385), with the column elution being accelerated by placing it under a nitrogen pressure of 34.474 kPa.

'Biotage' Refers to the use of the Biotage Flash 40 system using a pre-prepared normal phase silica column, with solvent elution accelerated by applying the mobile phase under nitrogen pressure up to 137.896 kPa.

Thin layer chromatography (TLC) uses 60 F ₂ 54 silica gel plates of 5x10 cm size (e.g. Merck Art 5719) with visualization by detectors operating in the UV region of electromagnetic radiation, unless otherwise stated.

If the products are purified by preparative HPLC, it is reverse-phase HPLC on a C ₁₈ column (1" Dynamax™) eluting with a gradient of acetonitrile solution (containing 0.1% trifluoroacetic acid solution) in water (containing 0.1% trifluoroacetic acid solution) and the resulting products are obtained as trifluoroacetates of the products.

Standard automated preparative HPLC columns, conditions and eluents:

Automated preparative high-performance liquid chromatography (autopreparative HPLC) is performed on a Supelco™ ABZ+ column (particle size 5pm, column height 100 mm, column internal diameter 22 mm) eluting with solvent mixtures consisting of:

1/ 0.1% solution of formic acid in water and ·* · ·« • ·· · ♦ · • » » ♦ • * · · ♦ • · · · · · · · · ·· · ··· ···« ·· ·

2/ 0.05% solution of formic acid in acetonitrile.

The eluent is expressed as a percentage of solution 2/ in the solvent mixture. The flow rate is 4 ml per minute. Unless otherwise stated, the elution is carried out with a gradient from 5 to 95% over 20 minutes.

LC/MS systems:

Systems for coupling mass spectrometry with high-performance liquid chromatography

LC/MS System A - A

The Supelco™ ABZ+ column (column height 3.3 cm, internal diameter 4.6 mm) is eluted with the solvent system:

A - 0.1% by volume formic acid solution + 0.077% w/v ammonium acetate in water and B - a mixture of acetonitrile and water in a ratio of 95:5 containing 0.05% by volume formic acid.

Gradient elution: 100% A - 0.7 minutes; gradient of the A+B mixture from 0% B to 100% B in 3.5 minutes; 100% B - 3.5 minutes; return to 0% B in 0.3 minutes. Positive and negative electrospray ionization is used.

LC/MS System B - A

The Supelco™ ABZ+ column (column height 5 cm, internal diameter 2.1 mm) is eluted with the following solvent system:

A - 0.1% by volume formic acid + 0.077% by weight/volume ammonium acetate in water and

B - a mixture of acetonitrile in water in the ratio 95:5 + 0.05%

• ♦ · · · · · · · · · · · · · ·· ··· of formic acid.

Gradient elution: 0 - 100% B in 3.5 minutes; 100% B in 1.50 minutes, return to 0% B in 0.50 minutes. Positive and negative electrospray ionization is used.

LC/MS System C - A

The Supelco™ ABZ+ column (column height 3.3 cm, internal diameter 4.6 mm) is eluted with the solvent system:

A - 0.1% by volume formic acid + 10 mmol ammonium acetate in water and

B - a mixture of acetonitrile in water in a ratio of 95:5 containing 0.05% by volume of formic acid solution.

Gradient elution: 100% A - 0.7 minutes; gradient of solvent mixture A+B from 0% B to 100% B in 3.7 minutes; 100% B - 0.9 minutes; return to 0% B in 0.2 minutes. Positive and negative electrospray ionization is used.

Intermediates

Intermediate 1 (6R-{6-(2,2-diphenyl-ethylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-2,2-dimethyl-tetrahydro-(3aR,6aR)-furo[3,4d]-[ 1,3]dioxol-4R-yl)-methanol

To 0.24 g (1.92 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethyl-amine (prepared from the corresponding bis-hydrochloride by neutralization with a small amount of solid sodium hydroxide in methanol) was added 0.20 g (0.384 mmol) of 2-chloro-N-(2,2-diphenylethyl)-2,3,0-(1-methyl-ethylidene)-adenosine (preparation no. 3 WO 94/17090). The solvent was removed by evaporation. To the resulting residue was added 0.7 ml of DMSO to form a suspension which was heated at 90°C for 25 hours. The cooled reaction _mixture was purified by flash chromatography on a silica gel column eluting with DCM, methanol and ammonia (200:5:1 to 200:10:1) to afford the title compound as 0.226 g of a white solid.

LC/MS system A: Rt= 3.97 minutes, m/z = 611 MH+.

Intermediate 2 (3aS, 4S, 6R, 6aR)-6-{6-(2,2-diphenyl-ethylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-2,2-dimethyl-tetrahydro-furo[3,4-d]-[1,3]-dioxol-4-carboxylic acid

To a stirred purple solution of 0.292 g (1.85 mmol) potassium permanganate and 0.166 g (2.96 mmol) potassium hydroxide in 1 ml water at 0°C was added dropwise a solution of 0.226 g (0.370 mmol) intermediate 1 in 3 ml 1,4-dioxane. The resulting solution was stirred at 0°C for 3 h and then treated with solid sodium metabisulfite until the purple color disappeared. The resulting gray suspension was acidified to pH 3 by adding 2N hydrochloric acid and the product was extracted three times with 20 ml ethyl acetate. The organics were washed with 20 ml saturated sodium chloride solution and dried over magnesium sulfate, then concentrated in vacuo to give 0.100 g of the title compound as a white solid.

LC/MS system A: Rt= 3.96 minutes, m/z = 625 MH+.

Intermediate 3 {2-chloro-9-[6S-(3-ethyl-[1,2,4]oxadiazol-5-yl)-2,2-dimethyl-tetrahydro-(3aR,6aS)-furo[3,4-d]-[1,3]dioxol-4R-yl]-9H-purin-6-yl}(2,2-diphenyl-ethyl)-amine

To a stirred mixture of 0.50 g (0.935 mmol) of (3aS, 4S, 6R, 6aR)-6-[2chloro-6-(2,2-diphenyl-ethylamino)-purin-9-yl]-2,2-dimethyl-tetrahydro39 • »··· furo[3,4-d]-[1,3]-dioxole-4-carboxylic acid [Preparation 4 of International Patent Application WO 94/17090] in 10 ml of anhydrous tetrahydrofuran at 0°C was added 0.218 ml (1.214 mmol) of diisopropyl-ethylamine. To the cooled stirred mixture was added 0.150 ml (1.214 mmol) of pivaloyl chloride and the mixture was stirred at 0°C for 1 hour. The mixture was cooled to -10°C, 0.160 g (1.87 mmol) of N-hydroxypropionamidine in 3 ml of anhydrous tetrahydrofuran was added dropwise and the resulting solution was stirred for 1 hour. The mixture was allowed to warm to room temperature and stirred for a further 20 hours. The solution was concentrated in vacuo and then azeotropically distilled with 10 ml of toluene twice. The yellow residue was redissolved in 15 ml of toluene and heated to 80°C for 1 hour with stirring. After cooling, the reaction mixture was concentrated in vacuo to give a yellow oil which was purified by flash chromatography on a silica gel column eluting with 35-50% ethyl acetate in cyclohexane to give the title compound as 0.430 g of a white solid.

TLC (35% ethyl acetate in cyclohexane): Rf = 0.58

Intermediate 4 (2R, 3R, 4S, 5S)-2-[2-chloro-6-(2,2-diphenyl-ethylamino)-purin-9-yl]-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-furan-3,4-diol

A solution of 0.375 mg (0.638 mmol) of intermediate 3 in 5.6 mL of trifluoroacetic acid and 1.4 mL of water was stirred under nitrogen at 5-10°C for 8.5 h, then concentrated in vacuo. The residue was azeotroped twice with toluene to give the title compound as a creamy white solid (0.340 mg).

LC/MS system B: Rt = 3.36 minutes, m/z = 548 MH+

Intermediate 5

2-chloro-N-(1-ethylpropyl)-adenosine

A mixture of 10.1 g (22.6 mM) of 2,6-dichloro-9-(2,3,5-tri-O-acetyl-S-Dribo-furanosyl)-9H-purine*\ 300 ml of isopropanol, 5 g of potassium carbonate and 2.17 g (24.84 mM) of 1-ethyl-propylamine was stirred at 20°C for 24 hours. The reaction mixture was heated to 54°C for 73 hours. The solvent was removed by evaporation in vacuo, 50 ml of water was added, the mixture was extracted three times with 80 ml of ethyl acetate and the combined extracts were dried over magnesium sulphate. 9.44 g of the title compound was obtained as a beige foam.

LC/MS system A: Rt = 2.66 minutes, m/z = 372 MH+.

** M. J. Robina and B. Uznanski, Canad. J. Chem, 1981, 59(17), 2608.

Intermediate 6 {6R-[2-chloro-6-(1-ethyl-propylamino)-purin-9-yl]-2,2-dimethyl-tetrahydro-(3aR,6aR)-furo[3,4-d][1,3]dioxol-4R-yl}-methanol

A mixture of 9.3 g (22.6 mmol) of intermediate 5, 35 ml of 2,2-dimethoxypropane, 250 ml of acetone and 8.1 g of para-toluenesulfonic acid was stirred at 20°C for 22 hours. The solvent was removed by evaporation in vacuo and the residue was treated with 200 ml of ethyl acetate, washed three times with 70 ml of saturated aqueous sodium bicarbonate solution. The aqueous wash was back-extracted with 50 ml of ethyl acetate. The combined organics were dried over magnesium sulfate and the solvent was removed by evaporation in vacuo. The residue formed was purified by flash chromatography on a silica gel column eluting with 50%, 60% and then 70% ethyl acetate in cyclohexane to give 5.67 g of the title compound as a white foam.

TLC S1O2 (50% ethyl acetate in cyclohexane): Rf = 0.17.

* *· ·< · • · · · « 9 · · • 9 9 9 9 * * · · · 9

9 9 9 9

999 9999 99 999 ·« • · ·

9

9 9

999

Intermediate 7 (3aS, 4S, 6R, 6aR)-6-[2-chloro-6-(1-ethyl-propylamino)-purin-9-yl]-2,2-dimethyl-tetrahydro-furo[3,4-d]-[1,3]dioxole-4-carboxylic acid

A mixture of 5.431 g (13.2 mmol) of intermediate 6, 0.157 g (1.32 mmol) of potassium bromide, 0.010 g (0.07 mmol) of TEMPO in 205 ml of ethyl acetate and 138 ml of saturated aqueous sodium bicarbonate solution was stirred vigorously for 20 minutes at 0°C. A mixture of 7.3 ml of sodium hypochlorite (13% active chloride), 0.420 g of solid sodium bicarbonate and 2 ml of water was added dropwise over 5 minutes. After 30 minutes, the other reagents (potassium bromide, TEMPO, sodium hypochlorite, solid sodium bicarbonate and water in the same amounts as above) were added. This addition is repeated after a further 30 minutes. One hour later, the reaction mixture is poured into a solution of 28 g of aqueous sodium sulfite in 400 ml of water and diluted with 100 ml of ethyl acetate. The mixture is shaken vigorously and the organic portion is washed with 100 ml of water. The combined aqueous portions are cooled to 0°C, acidified to pH 3 by adding 2M hydrochloric acid, extracted three times with 200 ml of ethyl acetate, dried over magnesium sulfate and the solvent is removed by evaporation in vacuo. 5.03 g of the title compound is obtained as a white foam.

LC/MS system B: _Rt = 3.25 minutes, m/z = 426 MH+.

Intermediate 8 {2-chloro-9-[6S-(3-ethyl-[1,2,4]oxadiazoph-5-yl)-2,2-dimethyl-tetrahydro-(3aR,6aS)-furo[3,4-d]-[1,3]-dioxol-4R-yl]-9H-purin-6-yl}( 1 -ethyl-propyl)-amine *9 t

• ·

9 9 • · in 12 ml

A solution of 0.7 g (1.647 mmol) of the intermediate in anhydrous tetrahydrofuran was treated at 0°C with 0.372 ml (2.14 mmol) of diisopropylethylamine and 0.263 ml (2.14 mmol) of pivaloyl chloride. The resulting solution was stirred at 0°C for 1.5 hours and then further cooled to -10°C. 0.289 g (3.29 mmol) of N-hydroxypropionamidine in 5 ml of tetrahydrofuran was added over 15 minutes. The solution was stirred at 05°C for 1 hour and then at room temperature for 20 hours. After concentration in vacuo, the reaction mixture was azeotropically distilled twice with 20 ml of toluene. The resulting residue was dissolved in 15 ml of toluene and the solution was heated to 80°C for 1 hour. The cooled solution was concentrated in vacuo, purified by flash chromatography on a silica gel column eluting with 35% ethyl acetate in cyclohexane to give 0.780 g of the title compound as a clear oil.

TLC SiO ₂ (30% ethyl acetate in cyclohexane): Rf = 0.26.

LC/MS system B: _Rt = 3.53 minutes, m/z = 478 MH+.

Intermediate 9 (2R, 3R, 4S, 5S)-2-[2-chloro-6-(1-ethyl-propylamino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol

A solution of 0.78 g (1.63 mmol) of intermediate 8 in 5 ml of a 10:1 mixture of trifluoroacetic acid and water was stirred at 0°C for 4.5 h. The mixture was concentrated in vacuo and azeotropically distilled with 10 ml of toluene three times to give 0.705 g of the title compound as a pink solid.

LC/MS system B: _Rt = 3.05 minutes, m/z = 438 MH+.

Intermediate 10 {2-Chloro-9-[2,2-dimethyl-6S-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-(3aR,6aS)-furo[3,4-d]-[1,3]-dioxol-4R-yl]-9H-purin-6-yl}(1-ethyl-propyl)-amine

A solution of 0.7 g (1.647 mmol) of intermediate 7 in 12 ml of anhydrous tetrahydrofuran was treated at 0°C with 0.372 ml (2.14 mmol) of di-isopropylethylamine and 0.263 ml (2.14 mmol) of pivaloyl chloride. The resulting solution was stirred at 0°C for 1.5 hours, then cooled to -10°C, and 0.244 g (3.29 mmol) of N-hydroxyacetamidine in 5 ml of tetrahydrofuran was added over 15 minutes. The solution was stirred at 0-5°C for 1 hour, then at room temperature for 20 hours. The reaction mixture was concentrated in vacuo and the residue was azeotropically distilled twice with 20 ml of toluene. The resulting residue was dissolved in 15 ml of toluene and the solution was heated to 80°C for 1 hour. The cooled solution was concentrated in vacuo and then purified by flash chromatography on a silica gel column eluting with 35% ethyl acetate in cyclohexane to provide the title compound as 0.762 g of a clear oil.

TLC SiO2 (30% ethyl acetate in cyclohexane): Rf = 0.24. LC/MS system B: R _t = 3.41 minutes, m/z = 464 MH+.

Intermediate 11 (2R, 3R, 4S, 5S)-2-[2-chloro-6-(1-ethyl-propylamino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol

A solution of 0.76 g (1.64 mmol) of intermediate 10 in 5 ml of a 10:1 mixture of trifluoroacetic acid and water was stirred at 0°C for 4.5 h. The mixture was concentrated in vacuo and the residue formed was azeotropically distilled three times with 10 ml of toluene to give 0.692 g of the title compound as a light pink solid. LC/MS system B: Rt = 2.92 min, m/z = 424 MH+.

Intermediate 12 2-chloroadenosine

At 0°C, 25 ml of anhydrous methanol was bubbled through with a stream of ammonia for 30 minutes. The solution was then added to a mixture of 2.000 g (4.5 mmol) of 2,6-dichloro-9-(2,3,5-tri-O-acetyl-B-D-ribo-furanosyl)9H-purine** in 5 ml of anhydrous methanol and heated to 20°C for 24 hours. After a further 6 hours, ammonia was bubbled through the solution again, and then after a further 20 hours. The solvent was removed by evaporation in vacuo and the residue was purified by flash chromatography on a silica gel column eluting with pure ethyl acetate to give 1.152 g of the resulting compound as a white solid.

TLC SiO ₂ (neat ethyl acetate): Rf = 0.15 ** MJ Robins and B. Uznanski, Canad. J. Chem, 1981, 59(17), 2608.

Intermediate 13 [6R-(6-amino-2-chloro-purin-9-yl)-2,2-dimethyl-tetrahydro-(3αR,

6αR)-furo-[3,4-d]-[1,3]-dioxol-4R-yl]-methanol

To a stirred solution of 0.700 g (2.3 mmol) of intermediate 12 in 70 ml of acetone were added 1.70 m (13.8 mmol) of 2,2-dimethoxypropane and 0.438 g (2.3 mmol) of para-toluenesulfonic acid and the reaction mixture was stirred overnight at 20°C. The solvent was removed by evaporation in vacuo and the reaction mixture was treated with 150 ml of ethyl acetate. The suspension was shaken three times with 50 ml of saturated aqueous sodium bicarbonate solution and with water. The aqueous washings were back-extracted with 50 ml of ethyl acetate. The combined organics were dried over magnesium sulfate and the solvent was removed by evaporation in vacuo to give 0.651 g of the title compound as a white solid.

• ·

TLC SiO ₂ (pure ethyl acetate): Rf = 0.33

Intermediate 14 (3aS, 4S, 6R, 6aR)-6-(6-amino-2-chloro-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d]-[1,3]dioxole-4-carboxylic acid

A solution of 0.400 g (1.2 mmol) of intermediate 13 in 12 ml of 1,4-dioxane and 4 ml of water was added dropwise at 0°C over 20 minutes to a stirred solution of 0.924 g (5.8 mmol) of potassium permanganate and 0.524 g (9.4 mmol) of potassium hydroxide in 4 ml of water. The mixture was stirred for a further 3 hours at 0°C, solid sodium metabisulfite was added until the violet colour disappeared, and then the mixture was acidified to pH 3 by adding 2N hydrochloric acid. The mixture was extracted three times with 50 ml of ethyl acetate, the combined organic solutions were washed with saturated sodium chloride solution, dried over magnesium sulphate and the solvent was removed by evaporation in vacuo. 0.316 g of the title compound was obtained as a white solid.

TLC _SiO2 (pure ethyl acetate): Rf= 0.10.

Intermediate 15

2-Chloro-9-[2,2-dimethyl-6S-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-(3aR,6aS)-furo[3,4-d]-[1,3]dioxol-4R-yl]-9H-purin-6-yl-amine

A mixture of 0.400 g of intermediate 14 and 0.154 ml of di-isopropylethylamine in 10 ml of tetrahydrofuran was stirred under nitrogen at room temperature for 15 minutes and then cooled to 0°C. After addition of 0.18 ml of pivaloyl chloride, the mixture was stirred at 0°C for 1 hour. The mixture was treated with 0.196 g of N-hydroxyacetamidine, stirred at 0°C for 1 hour and then allowed to warm to room temperature overnight. The reaction mixture was concentrated in vacuo, 20 ml of toluene was added and the mixture was heated to 80°C for 3 hours. The cooled mixture was evaporated in vacuo. The residue formed was purified by flash chromatography on a silica gel column eluting with a mixture of dichloromethane, ethanol and 880 ammonia in a ratio of 100:8:1 to give 0.328 g of the title compound as a white solid.

TLC S1O2 (dichloromethane : ethanol : 880 ammonia = 100:8:1):

_Rf = 0.47

Intermediate 16

2-Chloro-9-[6S-(3-ethyl-[1,2,4yoxadiazol-5-yl)-2,2-dimethyl·tetrahydro-(3aR,6aS)-furo[3,4-d]-[1,3]dioxol-4R-yl]-9H-purin-6-yl-amine

A mixture of 0.500 g of intermediate 14 and 0.318 ml of di-isopropylethylamine in 10 ml of tetrahydrofuran was cooled to 0°C and stirred under nitrogen for 15 min. After addition of 0.225 ml of pivaloyl chloride, the mixture was stirred at 0°C for 1 h. The mixture was treated with 0.246 g of N-hydroxy-propionamidine in 2 ml of tetrahydrofuran, stirred at 0°C for 1 h, and then allowed to warm to room temperature overnight. The cooled reaction mixture was evaporated in vacuo. The residue formed was purified by flash chromatography on a silica gel column, eluting with a 100:8:1 mixture of dichloromethane, ethanol and 880 ammonia to give 0.389 g of the title compound as a pale yellow foam.

TLC SiO2 (dichloromethane : ethanol : 880 ammonia = 100:8:1):

Rf - 0.5 • · · · ·

Intermediate 17 (2R, 3R, 4S, 5S)-2-(6-amino-2-chloropurin-9-yl)-5-(3-methyl[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-acetate

A solution of 0.488 g of intermediate 15 in 20 mL of acetic acid and 5 mL of water was heated at 100°C for 16 hours. The cooled reaction mixture was evaporated in vacuo to give the title compound as a brown oil (0.537 g).

TLC S1O2 (dichloromethane: ethanol: 880 ammonia = 100:8:1):

Rf - 0.14.

Intermediate 18 (2R, 3R, 4S, 5S)-2-(6-amino-2-chloro-purin-9-yl)-5-(3-ethyl-[1,2,4]-oxa-diazol-5-yl)-tetrahydro-furan-3,4-diol-acetate

A solution of 0.381 g of intermediate 16 in 15 ml of acetic acid and 3 ml of water was heated to 100 °C for 4.5 hours and then maintained at 119 °C for 3 hours. After adding 5 ml of acetic acid and 1 ml of water, the reaction mixture was heated at 119 °C for 8 hours. The cooled reaction mixture was evaporated in vacuo to give 0.410 g of the title compound as a light brown solid.

TLC S102 (dichloromethane: ethanol: 880 ammonia = 100:8:1): Rf = 0.15.

Intermediate 19 [6R-(6-amino-2-phenyl-ethylamino-purin-9-yl)-2,2-dimethyltetrahydro-(3aR, 6aR)-furo[3,4-d]-[1,3]-dioxol-4R-yl]-methanol

A solution of 10.0 g (19.5 mmol) of intermediate 13 and 12.2 ml (97.3 mmol) of phenylethylamine was heated at 110 °C for 7 h. The reaction mixture was diluted with 400 ml of ethyl acetate and washed with 1M hydrochloric acid. The aqueous phase was extracted three times with 200 ml of ethyl acetate and the combined organic extracts were dried over magnesium sulfate. The solvent was removed in vacuo and the product was purified by column chromatography on silica eluting with 5% methanol in dichloromethane to give 7.61 g of the title compound as a brown oil.

TLC SiO ₂ (dichloromethane : methanol = 10:1) Rf = 0.28

Intermediate 20 (3aS, 4S, 6R, 6aR)-6-(6-amino-2-phenylethyl-amino-purin-9-yl)-2,2-dimethyl-tetrahydro-furo[3,4-d]-[1,3]dioxole-4-carboxylic acid

A solution of 4.0 g (9.38 mmol) of intermediate 19 in 54 mL of 1,4-dioxane and 13.3 mL of water was added dropwise to a stirred solution of 7.5 g (46.9 mmol) of potassium permanganate and 4.24 g (75 mmol) of potassium hydroxide in 84 mL of water at 0°C over 30 min. The mixture was stirred at 0°C for an additional 1 h. Excess potassium permanganate was removed by portionwise addition of solid sodium metabisulfite. The solution was filtered through a pad of Celite and washed with 1,4-dioxin. The filtrate was concentrated in vacuo to a volume of 20 mL, acidified by addition of concentrated hydrochloric acid. The solid was filtered and dried over phosphorus pentoxide overnight to give 2.25 g of the title compound as a white solid.

TLC SiO ₂ (dichloromethane : methanol = 5:1) Rf = 0.44

Intermediate 21

2-Phenylethyl-amino-9-[6S-(3-ethyl-[1,2,4]oxadiazol-5-yl)-2,2-dimethyl-tetrahydro-(3aR,6aS)-furo[3,4-d]-[1,3]dioxol-4R-yl]-9H-purin-6-yl-amine

To a solution of 0.500 g (1.14 mmol) of intermediate 20 in 10 mL of DME was added 0.168 g (2.28 mmol) of N-hydroxyacetamidine and 0.654 g (2.28 mmol) of EEDQ and the reaction mixture was heated to reflux for 2 h. After addition of 0.168 g (2.28 mmol) of N-hydroxyacetamidine and 0.654 g (2.28 mmol) of EEDQ, the reaction mixture was heated to reflux for 4 days, the solvent was removed by evaporation in vacuo and the residue was purified by flash chromatography on a silica gel column eluting with 5% methanol in ethyl acetate to give 0.256 g of the title compound as a yellow foam.

TLC SiO2 (ethyl acetate:methanol 19:1): Rf = 0.33

Intermediate 22 {2-Chloro-9-[2,2-dimethyl-6R-(3-propyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-(3aS,6aR)-furo-[3,4-d]-[1,3J-dioxol-4S-yl]-9H-purin-yl}(2,2-diphenylethyl)-amine

To a stirred mixture of 0.428 g (0.8 mmol) of (3aS, 4S, 6R, 6aR)-6-[2chloro-6-(2,2-diphenyl-ethylamino)-purin-9-yl)-2,2-dimethyl-tetrafuro[3,4-d]-[1,3]-dioxole-4-carboxylic acid (Preparation 4, International Patent Application WO 94/17090) in 8 ml of anhydrous tetrahydrofuran at 0°C was added 0.181 ml (1.04 mmol) of diisopropyl-ethylamine. To the cooled stirred mixture was added 0.128 ml (1.04 mmol) of pivaloyl chloride and the mixture was stirred at 0°C for 1 hour. 0.163 g (1.6 mmol) of N-hydroxy-butyramidine in 7 ml of anhydrous tetrahydrofuran was added dropwise over 10 minutes and the resulting solution was stirred at 0°C for 1 hour. The mixture was allowed to warm to room temperature and stirred for a further 20 hours. The solution was concentrated in vacuo and then azeotropically distilled twice with 10 ml of toluene. The yellow residue was redissolved in 15 ml of toluene and heated to 80°C for 1 hour with constant stirring. After cooling, the reaction mixture was concentrated in vacuo to give a yellow oil which was purified by flash chromatography.

by silica gel column chromatography eluting with 40% ethyl acetate in cyclohexane to give the title compound as 0.392 g of a clear oil.

LC/MS system A: Rt - 5.27 minutes, m/z = 602 MH+.

Intermediate 23 (2R, 3R, 4S, 5S)-2-[2-chloro-6-(2,2-diphenyl-ethylamino)-purin-9-yl]~ -5-(3-propyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol

A solution of 0.392 mg (0.652 mmol) of intermediate 22 in 10 mL of acetic acid and 2.5 mL of water was stirred under nitrogen at 5-10°C for 26 h, then concentrated in vacuo. The resulting residue was azeotropically distilled twice with toluene to give the title compound as a creamy white foam (0.355 mg).

LC/MS system B: Rt = 3.41 minutes, m/z = 562 MH+.

Intermediate 24 {2-Chloro~9-[2,2-dimethyl-6S-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-(3aR,6aS)-furo-[3,4-dJ-[1,3]-dioxol-4R-yl]-9H-purin-yl}(2,2-diphenylethyl)-amine

To a stirred mixture of 0.15 g (0.28 mmol) of (3aS, 4S, 6R, 6aR)-6-[2chloro-6-(2,2-diphenyl-ethylamino)-purin-9-yl)-2,2-dimethyl-tetrafuro[3,4-d]-[1,3]-dioxole-4-carboxylic acid (Preparation 4, International Patent Application WO 94/17090) in 4 ml of anhydrous tetrahydrofuran at 0°C was added 0.63 ml (0.364 mmol) of diisopropyl-ethylamine. To the cooled stirred mixture was added 0.045 ml (0.364 mmol) of pivaloyl chloride, and the mixture was stirred at 0°C for 1.5 hours. 0.042 g (0.56 mmol) of N-hydroxyacetamidine was added portionwise over 10 minutes, and the resulting solution was stirred at 0°C for 1 hour. The mixture was allowed to warm to room temperature and stirred for a further 20 hours. The solution was concentrated in vacuo and then azeotropically distilled twice with 10 ml of toluene. The resulting yellow residue was redissolved in 7 ml of toluene and the solution was heated to 80°C with stirring for 1 hour. The cooled reaction mixture was concentrated in vacuo to give 0.146 g of the title compound as a yellow oil.

LC/MS system B: Rt= 3.58 minutes, m/z = 574 MH+.

Intermediate 25 (2R, 3R, 4S, 5S)-2-[2-chloro-6-(2,2-diphenyl-ethylamino)-purin-9-yl]-5-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-furan-3,4-diol

A solution of 0.146 g (0.255 mmol) of intermediate 24 in 10 ml of acetic acid and 2.5 ml of water was stirred at 100°C under nitrogen for 37 h and then concentrated in vacuo. The residue was azeotroped twice with 10 ml of toluene to give 0.132 g of the title compound as a yellow solid. LC/MS system B: Rt = 3.23 min, m/z = 534 MH+.

Intermediate 26 {2-Chloro-9-[6S-(3-cyclopropyl-[1,2,4]oxadiazol-5-yl)-2,2-dimethyl-tetrahydro-(3aR,6aS)-furo[3,4-d]-(1,3]-dioxol-4R-yl]-9H-purin-6-yl}(1-ethyl-propyl)-amine

In 33 ml of tetrahydrofuran, 2.13 g (5 mmol) of intermediate 7 were dissolved under nitrogen, the solution was cooled to 5°C and 1.9 ml (11 mmol) of N,N-diisopropylethylamine and 0.67 ml (5.5 mmol) of trimethylacetyl chloride were added. The mixture was warmed to room temperature over 1 hour. After cooling to 5°C, 0.61 g (6 mmol) of N-hydroxycyclopropanecarboxamidine** was added and the reaction mixture was stirred for 16 hours and warmed to room temperature. The solvent was removed by evaporation in vacuo and the residue was dissolved in 100 ml of toluene and heated to reflux (120°C) for 24 hours under nitrogen. The toluene was evaporated in vacuo and the product was purified by solid phase extraction using a 10 g (SiO2) pre-prepared Varian Mega Bonded Elut column eluting with a 1:2 mixture of ethyl acetate and cyclohexane to give 2.170 g of the resulting yellow gum.

LC/MS system A: Rt = 4.80 minutes, m/z=490 MH+ ** W.J. Fanshawe, V.J. Bauer, S.R. Safir, D.A. Blickens and S.J. Riggi, J. Med. Chem, 1969, 12, 381.

Intermediate 27 (2R, 3R, 4S, 5S)-2-[2-chloro-6-(1-ethyl-propylamino)-purin-9-yl]-5-(3-cyclo-propyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol

At 0°C, 2.1 g (4.5 mmol) of intermediate 26 was dissolved in 25 ml of a 9:1 mixture of trifluoroacetic acid and water over 6 hours under nitrogen with constant stirring and left in a refrigerator (4°C) for 16 hours. The mixture was concentrated in vacuo and the residue was slowly poured into 150 ml of saturated sodium bicarbonate solution, extracted three times with 50 ml of dichloromethane, washed with saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated to give 2 g of the resulting compound as a yellow-white solid.

LC/MS system B: _Rt = 3.22 minutes, m/z = 450 MH+.

Intermediate 28 {6R-(2-chloro-6-phenethyl-amino-purin-9-yl)-2,2-dimethyl-tetrahydro-(3aR, 6aR)-furo[3,4-d]-[1,3]-dioxol-4R-yl}-methanol

A mixture placed in a sealed tube (i.e. Reactivial™) of 0.1 g (0.224 mmol) of 4R-acetoxy-5R-acetoxy-methyl-2R-(2,6-dichloropurin-9-yl)-tetrahydro-furan-3R-yl-acetic acid ester**, 0.034 ml (0.27 mmol) of 2-phenylethylamine and 0.047 ml (0.27 mmol)

A* A ·· A

A AAA AAA

AAA A A AAA di-isopropyl-ethylamine in 2 ml isopropanol is heated to 52°C for 17.5 hours. The reaction mixture is then diluted with 1 ml methanol. After adding 0.077 ml (0.336 mmol) of a 25% by weight solution of sodium methoxide in methanol, the mixture is stirred for 3.5 hours at room temperature. 0.2 ml acetic acid is added to the reaction mixture. After removing the volatile fraction, a residue is obtained, which is dissolved in 2.5 ml acetone and the mixture is treated with 0.35 ml 2,2-dimethoxypropane and 0.081 g paratoluenesulfonic acid. After 66 hours, 3 ml acetone and 0.35 ml 2,2-dimethoxypropane are added and after 90 hours, 81 mg paratoluenesulfonic acid is added. After a further 21 hours, the reaction mixture is evaporated in a stream of air. The resulting mixture was stirred with 4 mL of saturated aqueous sodium carbonate for 10 min, extracted with 3 mL of ethyl acetate three times, dried over magnesium sulfate and evaporated in vacuo to give 0.118 g of the title compound as a light brown gum.

LC/MS system A: Rt= _4.50 minutes, m/z = ⁴⁴⁶ MH ₊ for _{C21H2435CIN504 .}

** M. J. Robins and B. Uznanski, Canad. J. Chem, 1981, 59(17), 2608.

Intermediate 29 {6R-[2-chloro-6-(2-cyclohexyl-ethylamino)-purin-9-yl]-2,2-dimethyltetrahydro-(3aR, 6aR)-furo[3,4-d]-[1,3]dioxol-4R-yl}-methanol

Intermediate 29 was prepared in a similar manner to intermediate 28 using 0.034 g (0.27 mmol) of 2-cyclohexylethylamine to give 0.116 g of the title compound as a light brown foam.

LC/MS system A: R _t = 4.93 minutes, m/z = 452 MH+ for C ₂₁ H ₃₀ ³⁵ CIN ₅ O ₄ .

·· ·

Intermediate 30 {6R-[2-chloro-6-(3,3-dimethyl-butylamino)-purin-9-yl]-2,2-dimethyltetrahydro-(3aR, 6aR)-furo[3,4-d]-[1,3]dioxol-4R-yl}-methanol

Intermediate 30 was prepared in a similar manner to intermediate 28 using 0.036 ml (0.27 mmol) of 3,3-dimethylbutylamine to give the title compound as 0.111 g of a white solid with 88% purity.

LC/MS system A: R _t = 4.93 minutes, m/z = 452 MH+ for C ₂ iH 3 ^{o 35} CIN ₅ 0 ₄ .

Intermediate 31 {6R-(6-phenethyl-amino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-2,2-dimethyl-tetrahydro-(3aR, 6aR)-furo[3,4-d]-[1,3]-dioxol-4R-yl)-methanol

A mixture of 0.118 g (0.265 mmol) of intermediate 28 and 0.168 g (1.344 mmol) of 2-(1-methyl-1H-imidazol-4-yl)ethylamine (prepared from the corresponding bis-hydrochloride by neutralization with a slight deficiency of solid sodium hydroxide in methanol) in a mixture of 0.3 ml of diisopropylethylamine and 0.3 ml of DMSO was heated at 104 °C in a sealed tube (e.g. Reacti-vial™) for 20 hours. The cooled reaction mixture was diluted with 5 ml of 0.5 M aqueous sodium hydroxide solution and extracted four times with 5 ml of dichloromethane. The combined extracts were filtered through a Varian Mega Bond Elut column (5g Si, 20ml size), eluting with dichloromethane, 50% ethyl acetate/cyclohexane, ethyl acetate, and then 10% methanol/ethyl acetate. The fractions containing the desired product were combined and evaporated in vacuo to give 0.107g of the final product as a clear gum.

TLC (10% methanol in ethyl acetate, visualization with UV light): R _f - 0.13.

Intermediate 32 {6R-{6-(2-cyclohexyl-ethylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-2,2-dimethyl-tetrahydro-(3aR,6aR)furo[3,4-dH1,3]-dioxol-4R-yl)-methanol

Intermediate 32 was prepared in a similar manner to intermediate 31 using 0.116 g (0.257 mmol) of intermediate 29. The resulting compound was obtained as 0.09 g of a clear gum.

TLC (10% methanol in ethyl acetate, visualization with UV light): Rf =0.13.

Intermediate 33 {6R-{6-(3,3-Dimethyl-butylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethyl-amino]-purin-9-yl}-2,2-dimethyl-tetrahydro-(3aR,6aR)-furo-[3,4d]-[1,3]-dioxol-4R-yl)-methanol

Intermediate 33 was prepared in a similar manner to intermediate 31 using 0.111 g (0.261 mmol) of intermediate

30. The resulting compound is obtained as 0.097 g of a clear gum.

TLC (10% methanol in ethyl acetate, visualized by UV light): Rf = 0.13

Intermediate 34 (3aS, 4S, 6R, 6aR)-6-{6-phenethyl-amino-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-2,2-dimethyl-tetrahydro-furof3,4-d]-11,3]dioxol-4-carboxylic acid

To a stirred mixture of 0.1 g potassium hydroxide and 0.158 g (1 mmol) potassium permanganate in 1 ml water at 0°C, add • 1 4

4

4· 4 • · «4

4444444 44 a solution of 0.107 g (0.2 mmol) of intermediate 31 in 1.6 ml of dioxane was added dropwise over 5 min. The mixture was stirred in an ice-water bath for 4 h. Solid sodium metabisulfite was added until the purple color disappeared and the mixture was filtered through a short and pressed pad of Harbourlite. The resulting aqueous solution was carefully acidified to pH 3-4 by adding 2M aqueous hydrochloric acid and washed three times with 5 ml of ethyl acetate. The resulting aqueous solution was lyophilized to give a white solid which was extracted once with 3 ml of methanol and then twice with 1 ml of methanol to give the final product as 0.084 g of a creamy white solid.

LC/MS system C: R _t = 2.43 minutes, m/z = 549 MH+.

Intermediate 35 (3aS, 4S, 6R, 6aR)-6-{6-(2-cyclohexyl-ethylamino)-2-[2-(1 methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-2,2-dimethyl-tetrahydrofuro-[3,4-d]-[1,3]-dioxol-4-carboxylic acid

Intermediate 35 was prepared in a similar manner to intermediate 34 using 0.09 g (0.17 mmol) of intermediate 32. The resulting compound was obtained as 0.081 g of a creamy white solid.

LC/MS system C: R _t = 2.61 minutes, m/z = 555 MH+

Intermediate 36 (3aS, 4S, 6R, 6aR)-6-{6-(3,3-dimethyl-butylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-2,2-dimethyl-tetrahydrofuro[3,4-d]-[1,3]-dioxol-4-carboxylic acid

While stirring, 0.09 g (1.52 mmol) of crushed potassium hydroxide was dissolved in 0.5 ml of water. During stirring, 0.158 g (0.95 mmol) of potassium permanganate was added and the mixture was cooled to ♦ 4444 44 • 4 · 0°C. To the cooled mixture, a pre-cooled solution of 0.097 g (0.19 mmol) of intermediate 33 dissolved in 1.6 ml of 1,4-dioxane and 0.5 ml of water was added and the mixture was cooled to 0°C again. The reaction mixture was stirred at 0°C for 3 hours and 0.15 g of solid sodium metabisulfite was added to the mixture until the purple color disappeared. Insoluble material was removed by filtration through a plug of Harborlite and washed with 10 ml of water. The aqueous mixture was extracted twice with 20 mL of dichloromethane. The combined organics were concentrated in vacuo to give the title compound as 0.064 g of a yellow oil.

LC/MS system C: _Rt = 2.44 minutes, m/z = 529 MH+.

Intermediate 37

2-(pyridin-2-yl-amino)-ethylamine

Under nitrogen atmosphere, 10.00 g (63.3 mmol) of 2-bromopyridine was added dropwise to 76.00 g (126.6 mmol) of 1,2-diaminoethane with constant stirring at 20°C. The reaction mixture was stirred at 20°C for 4 hours and then heated under reflux for 24 hours. The reaction mixture was concentrated in vacuo and purified by flash chromatography on a silica gel column, eluting with a 30:8:1 mixture of dichloromethane, ethanol and ammonia, to give 1.23 g of the title compound as a red oil.

TLC S1O2 (dichloromethane, ethanol, ammonia = 30:8:1): Rf = 0.14. Mass spectrum: m/z 138 (MH+ for C7H11N3).

Intermediate 38

N-Hydroxy-propionamidine

A mixture of 20 ml (280 mmol) of propionitrile, 78 g (560 mmol) of potassium carbonate and 19,000 g (280 mmol) of hydroxylamine hydrochloride in 400 ml of ethanol was stirred at room temperature for 15 minutes and slowly heated to reflux over 1 hour, then refluxed for 7 hours. After cooling, the mixture was filtered through a plug of Harborlite and washed with 100 ml of ethanol. The solvent was evaporated in vacuo and the residue was azeotropically distilled three times with 100 ml of toluene to give 17 g of the title compound as a slightly colored oil.

TLC SiO ₂ (5% methanol/chloroform/1% ammonia): Rf = 0.21.

Intermediate 39

3-Ethyl-5-(6R-methoxy-2,2-dimethyl-tetrahydro-(3aR,6aR)-furo-[3,4d]-[1,3]-dioxol-4S-yl)-[1,2,4]-oxadiazole

A mixture of 14.800 g (68 mmol) of (3aS,4S,6R,6aR)-methoxy-2,2-dimethyltetrahydro-furo-[3,4-d]-[1,3]-dioxole-4-carboxylic acid (prepared according to the procedure for the preparation of intermediate 1 in international patent application WO 98/28319), 9.200 g (68 mmol) of 1-hydroxy-benz-triazole and 13.000 g (68 mmol) of 1-(3-dimethyl-amino-propyl)-3-ethyl-carbodiimide hydrochloride in 200 ml of dimethylformamide was stirred overnight at room temperature. After addition of a solution of 6.000 g (68 mmol) of intermediate 38 in 10 ml of dimethylformamide, the mixture was heated to 70°C overnight. After cooling, the solvent was removed by evaporation in vacuo. The residue formed was taken up in 100 ml of ethyl acetate, washed twice with 100 ml of 10% citric acid and once with 100 ml of water. The organic portion was dried over magnesium sulfate and evaporated in vacuo to give the title compound as a colorless gum (17.00 g).

LC/MS system C: _Rt =1.77 minutes, m/z = 271 MH+.

« ♦··· • ·

Intermediate 40

Acetic acid 4S-acetoxy-2R-(3-ethyl-[1,2,4]oxadiazol-5-yl)-5S-methoxy-tetrahydro-furan-3R-yl ester

A mixture of 17 g (62 mmol) of intermediate 39 and 3 ml of concentrated hydrochloric acid in 200 ml of methanol was heated under reflux overnight. After cooling, the mixture was evaporated in vacuo to 50% volume and 50 ml of pyridine was added. The mixture was then evaporated in vacuo to approximately 25% of the original volume. After adding a further 100 ml of pyridine, the mixture was evaporated in vacuo. The residue formed was treated with 150 ml of anhydrous pyridine and the mixture was treated with 50 ml (excess) of acetic anhydride, followed by 0.38 g (3 mmol) of DMAP. The mixture was stirred at room temperature overnight. The mixture was evaporated, the residue was treated with 200 ml of ethyl acetate and washed twice with 100 ml of 10% citric acid solution and 100 ml of water, dried over magnesium sulfate and the solvent was removed by evaporation in vacuo. The residue formed was purified using flash chromatography on a Biotage column (3x90g, SiO2) eluting with 30% cyclohexane in ethyl acetate to give 17.500 g of the title compound as a colorless solid.

TLC S1O2 (50% cyclohexane solution in ethyl acetate): Rf - 0.52

Intermediate 41

Acetic acid 4S-acetoxy-2R-(2,6-dichloro-purin-9-yl)-5S-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3R-yl ester

A mixture of 0.829 g (4.3 mmol) of 2,6-dichloropurine in 5 ml of 1,1,1,3,3,3hexamethyldisilazane was heated under reflux overnight, and then the solvent was removed by evaporation in vacuo. The residue formed was azeotropically distilled three times with 5 ml of anhydrous toluene. To the residue formed in 2 ml of anhydrous acetonitrile was added 0.500 g (1.6 mmol) of intermediate 40 and 0.65 ml (4.3 mmol) of DBU.

The mixture was then cooled to 0°C and 0.9 ml (4.8 mmol) of TMSOTf was added. The mixture was allowed to warm to room temperature and heated under reflux overnight to give a dark red solution. After cooling, the mixture was poured into 5 ml of saturated bicarbonate solution and extracted three times with 10 ml of ethyl acetate. The combined organics were washed with 20 ml of water, dried over magnesium sulfate and the solvent was removed by evaporation in vacuo. The resulting residue was flash chromatographed on a Biotage column (8g, SiO2) eluting with 60% cyclohexane in ethyl acetate to give 0.599 g of the title compound as a white solid.

LC/MS system C: Rt = 3.32 minutes, m/z = 472 MH+.

Intermediate 42

Acetic acid 4S-acetoxy-2R-[6-azido-2-(1S-hydroxymethyl-2-phenyl-ethylamino)-purin-9-yl]-5S-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3R-yl ester

To a cooled mixture of 0.600 g (1.27 mmol) of intermediate 41 in anhydrous dimethylformamide at -10 to -15°C was added 0.088 g (1.35 mmol) of sodium azide. The mixture was stirred at -10°C for 2 hours, and then 0.388 g (2.8 mmol) of 3-(S)-(-)-2amino-3-phenyl-propanol in 1 ml of anhydrous dimethylformamide was added. The mixture was allowed to warm to room temperature and stirred overnight. After addition of 15 ml of water, the mixture was extracted three times with 15 ml of ethyl acetate. The combined organics were dried over magnesium sulfate and evaporated in vacuo. The residue formed was purified by flash chromatography on a Biotage column (8g, SiO ₂ ) eluting with 30% cyclohexane in ethyl acetate. 0.450 g of the title compound is obtained as a colorless gum.

LC/MS system C: Rt = 3.25 minutes, m/z = 593 MH+.

4«

Intermediate 43

Acetic acid 4S-acetoxy-2R-[6-amino-2-(1S-hydroxymethyl-2-phenyl-ethylamino)-purin-9-yl]-5S-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3R-yl ester

A mixture of 0.440 g (0.74 mmol) of intermediate 42 and 0.220 g (0.84 mmol) of triphenylphosphine in 5 ml of tetrahydrofuran was stirred overnight at room temperature. The solvent was evaporated in vacuo. The residue formed was purified by autopreparative HPLC to give 0.410 g of the title compound as an off-white solid. LC/MS system C: R _t = 2.77 minutes, m/z = 567 MH+.

• ··*·

Example 1 (2R, 3R, 4S, 5S)-2-{6-(2,2-diphenyl-ethylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol-bis(trifluoroacetate)

A solution of 0.050 g (0.08 mmol) of intermediate 2 in 2 ml of 1,4-dioxane was treated with 0.024 g (0.096 mmol) of EEDQ and 0.012 g (0.16 mmol) of N-hydroxyacetamidine. The resulting mixture was heated to 103°C with stirring for 6 days. The solution was concentrated in vacuo to give a yellow oil, to which was added a cooled solution of 0.9 ml of trifluoroacetic acid and 0.1 ml of water. The resulting solution was stirred at 0°C for 6 hours, then concentrated in vacuo and azeotropically distilled with toluene three times. The resulting product was purified by preparative HPLC eluting with 30-70% acetonitrile in water. 0.006 g of the title compound was obtained as a white solid.

LC/MS system A: _Rt = 3.98 minutes, m/z = 623 MH+.

Example 2 (2R,3R,4S,5S)-2-{6-(2,2-diphenyl-ethylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-{3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol-bis(difluoroacetate)

The resulting compound of Example 2 was prepared according to the procedure of Example 1 using 0.014 g (0.16 mmol) of N-hydroxypropionamidine. A solution of 0.050 g (0.08 mmol) of intermediate 2 in 2 ml of 1,4-dioxane was treated with 0.024 g (0.096 mmol) of EEDQ and 0.014 g (0.16 mmol) of N-hydroxypropionamidine. The resulting mixture was heated to 103°C with stirring for 6 days. The solution was concentrated in vacuo to give a yellow oil. To this residue was added a cooled solution of 0.9 ml of trifluoroacetic acid and 0.1 ml of water. The resulting solution was stirred at 0°C for 6 hours, concentrated in vacuo and azeotropically distilled with toluene three times.

• · · e • · · ·· ·

The residue formed was purified by preparative HPLC eluting with 30-70% acetonitrile in water to give 0.012 g of the title compound as a white solid.

LC/MS system A: Rt= 4.02 minutes, m/z = 637 MH+.

Example 3 (2R, 3R, 4S, 5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(pyrrolidin-3R-yl-amino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate.

A mixture of 0.034 g (0.062 mmol) of intermediate 4, 0.030 ml (0.311 mmol) of (3R)-(+ -3-aminopyrrolidine) and 0.03 ml of DMSO was heated to 80°C in a sealed tube (e.g. Reacti-vial™) for 28 hours. The crude product formed was purified by autopreparative HPLC and after lyophilization 0.017 g of the resulting compound was obtained as a white solid.

LC/MS system A: _Rt = 3.65 minutes, m/z = 598 MH+.

Example 4 (2R, 3R, 4S, 5S)-2-[2-(trans-4-amino-cyclohexyl-amino)-6-(2,2-diphenyl-ethylamino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol diformate

The resulting compound of Example 4 was prepared in a similar manner to Example 3 using 0.035 g (0.311 mmol) of trans-1,4-diamino-cyclohexane. After lyophilization, 0.013 g of the resulting compound was obtained as a white solid.

LC/MS system B: _Rt = 2.58 minutes, m/z = 626 MH+.

• · • · • ·

Example 5 (2R, 3R, 4S, 5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(1S-hydroxy-methyl-2-methyl-propylamino)-purin-9-yl]-5-(3-ethyl-[1,2,4}-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol formate

The resulting compound of Example 5 was prepared in a similar manner to the procedure of Example 3 using 0.032 g (0.311 mmol) of (S)-2amino-3-methyl-1-butanol. The reaction mixture was heated at 80-95°C for 3 days. After lyophilization, 0.005 g of the resulting compound was obtained as a white solid. LC/MS system B: Rt= 3.16 minutes, m/z = 615 MH+.

Example 6 (2R,3R,4S,5S)-2-[6-(1-Ethyl-propylamino)-2-(2-morpholin-4-yl-ethylamino)-purin-9-yl]-5-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol formate

0.069 g (0.163 mmol) of intermediate 11 and 0.107 ml (0.815 mmol) of 4-(2-aminoethyl)morpholine are dissolved in 0.03 ml of DMSO and the mixture is heated to 80°C in a sealed tube (e.g. Reactivial™) for 26 hours, followed by the addition of 0.053 ml (0.407 mmol) of 4-(2-aminoethyl)morpholine after the first 20 hours. The product is purified by autopreparative HPLC and after lyophilization 0.059 g of the resulting compound is obtained as a brown solid.

LC/MS system B: _Rt = 2.19 minutes, m/z = 517MH+.

Example 7 (2R, 3R, 4S, 5S)-2-{6-amino-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-methyl-1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-bis(trifluoroacetate) • ·

In a sealed tube (e.g. Reactivial™), a mixture of 0.048 g of intermediate 17 and 0.06 g of 2-(1-methyl-1H-imidazol-4-yl)-ethylamine in 0.05 ml of DMSO was heated at 90°C for 20 hours. The crude material was purified twice by autopreparative HPLC, followed by preparative HPLC eluting with 10-60% acetonitrile over 22 minutes. The solvent was removed by evaporation in vacuo and the residue was lyophilized to give 0.007 g of the title compound as a brown solid.

LC/MS system A: Rt =1.8 minutes, m/z 443 (MH+).

Example 8 (2R, 3R, 4S, 5S)-2-[6-amino-2-(2-pyridin-2-yl-ethylamino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol diformate

In a sealed tube (e.g. Reactivial™), 0.041 g of intermediate 18, 0.06 ml of 2-(2-amino-ethyl)-pyridine and 0.05 ml of DMSO were heated at 90 °C for 16 hours. The product was purified by autopreparative HPLC. The solvent was removed by evaporation in vacuo and the residue was lyophilized to give 0.011 g of the title compound as a light brown solid. LC/MS system B: Rt =1.92 minutes, m/z 4S4 (MH+).

Example 9 (2R,3R,4S,5S)-2-[6-amino-2-(1S-hydroxy-methyl-2-phenyl-ethyl-amino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.041 g of intermediate 18, 0.06 g of (S)-(-)-2-amino-3-phenyl-1-propanol and 0.05 ml of DMSO is heated to 90°C for 32 hours, and then the temperature of the reaction mixture is maintained at 110°C for 16 hours.

The product was purified twice by autopreparative HPLC. The solvent was removed by evaporation in vacuo and the residue was lyophilized to give 0.003 g of the title compound as a white solid.

LC/MS system B: _Rt = 2.36 minutes, m/z = 483 (MH+).

Example 9 (alternative preparation method)

2R-[6-amino-2-(1S-hydroxy-methyl-2-phenyl-ethylamino)-purin-9-yl]-5S-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3R,4S-diol formate

A mixture of 0.160 g (0.28 mmol) of intermediate 43 and 0.009 g (0.14 mmol) of potassium cyanide in 3 mL of methanol was stirred at room temperature for 30 min. The solvent was evaporated in vacuo and the residue was purified using autopreparative HPLC to give the title compound 0.050 g as a white solid.

LC/MS system C: Rt = 2.35 minutes, m/z = 483 MH+.

Example 10 (2R,3R,4S,5S)-2-{6-amino-2-[2-(1-methyl-1H-imidazol-4-yl)ethylamino]-purin-9-yl}-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)tetrahydrofuran-3,4-diol diformate

In a sealed tube (e.g. Reactivial™), a mixture of 0.041 g of intermediate 18, 0.06 g of 2-(1-methyl-1H-imidazol-4-yl)-ethylamine and 0.05 ml of DMSO was heated to 90°C for 32 hours, then the reaction mixture was maintained at 110°C for 16 hours. The product was purified by autopreparative HPLC, the solvent was removed by evaporation in vacuo and the residue was lyophilized to give 0.014 g of the title compound as a brown solid.

LC/MS system B: _Rt =1.88 minutes, m/z =457 (MH+).

• · *· * · · · • · · · • 9 9 9 4 • 4 9 4

Example 11 (2R, 3R, 4S, 5S)-2-(6-amino-2-cyclopentyl-amino-purin-9-yl)-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

A mixture of 0.048 g of intermediate 17 and 0.06 mL of cyclopentylamine in 0.05 mL of DMSO was heated at 90°C for 20 hours in a sealed tube (e.g. Reactivial™). The crude material was purified by autopreparative HPLC, the solvent was removed by evaporation in vacuo and the residue was lyophilized to give 0.006 g of the title compound as a yellow solid.

LC/MS system A: R _t =2.2 minutes, m/z = 403 (MH+)

Example 12 (2R, 3R, 4S, 5S)-2-[6-amino-2-(1S-hydroxymethyl-2-phenyl-ethyl-amino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.048 g of intermediate 17 and 0.06 g of (S)-(-)-2-amino-3-phenyl-1-propanol in 0.05 ml of DMSO was heated at 90°C for 20 h. The crude material was purified twice by autopreparative HPLC, the solvent was removed by evaporation in vacuo and the residue was lyophilized to give 0.002 g of the title compound as a white solid.

LC/MS system A: _Rt = 2.24 minutes, m/z = 469 (MH+).

Example 13 (2S, 3S, 4R, 5R)-2-(3-Ethyl-[1,2,4]oxadiazol-5-yl)-5-{6-(1-ethyl-propyl-amino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-tetrahydrofuran-3,4-diol-formate

The solution is heated to a temperature of 85-100°C in a nitrogen atmosphere for 8 days.

0.070 g (0.161 mmol) of intermediate 9 and 0.101 g (0.807 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethyl-amine in 0.03 ml of DMSO, followed by the addition of 0.101 g (0.807 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethyl-amine after 5 days. The product was purified by autopreparative HPLC. After lyophilization, 0.010 g of the resulting compound was obtained as a creamy white solid.

LC/MS system A: _Rt = 3.36 minutes, m/z = 526 MH+.

Example 14 (2R, 3R, 4S, 5S)-2-{6-(1-Ethyl-propylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

A mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.102 g (0.815 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethylamine in 0.03 ml of DMSO was heated to 85-100°C under nitrogen for 7 days, followed by the addition of 0.102 g (0.815 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethylamine after the first 5 days. The product was purified by autopreparative HPLC and lyophilized to give 0.013 g of the resulting compound as a beige solid.

LC/MS system A: _Rt = 3.32 minutes, m/z = 512 MH+.

Example 15 (2R, 3R, 4S, 5S)-2-(6-amino-2-phenethyl-amino-purin-9-yl)-5-(3methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol trifluoroacetate

A solution of 0.210 g (0.44 mmol) of intermediate 21 in 2 ml of a 9:1 mixture of trifluoroacetic acid and water was stirred at 20°C for 3 h and the solvent was removed by evaporation in vacuo. The residue formed was purified by preparative HPLC eluting with 10-90% acetonitrile in water and lyophilized to give 0.088 g.

the resulting compounds as yellow solids.

Mass spectrum m/z 439 (MH+ for C20H23N8O4).

Found: C 46.70; H 4.05; N 19.51;

for C20H22N8O4. _C2HF3O2 . _{0.5H2O calculated} : C 46.54; H 4.24; N 19.56.

Example 16 (2R, 3R, 4S, 5S)-2-[2-(trans-4-amino-cyclohexyl-amino)-6-(1-ethyl-propyl-amino)-purin-9-yl]-5-(3-methyl-[1,2,4]oxadiazoi-5-yl)-tetrahydrofuran-3,4-diol formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.093 g (0.815 mmol) of trans-1,4-diaminocyclohexane in 0.03 ml of DMSO is heated at 80-90°C for 66 hours, followed by the addition of 0.093 g (0.815 mmol) of trans-1,4-diaminocyclohexane after the first 20 hours. The product is purified by autopreparative HPLC and after lyophilization 0.063 g of the resulting compound is obtained as a brown solid.

LC/MS system B: Rt = 2.12 minutes, m/z = 502 MH+.

Example 17 (2R, 3R, 4S, 5S)-2-[6-(1-ethyl-propylamino)-2-(1S-hydroxymethyl-2-phenyl-ethylamino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.123 g (0.815 mmol) of 3-(S)-(-)2-amino-3-phenylpropanol in 0.03 ml of DMSO was heated at 80-95’C for 5.5 hours. The product was purified by autopreparative HPLC and after lyophilization, 0.014 g of the resulting compound was obtained as a yellow solid.

• 4 4

4 4 44

LC/MS system B: _Rt = 2.80 minutes, m/z = 539 MH+.

Example 18 (2R, 3R, 4S, 5S)-2-[6-1-ethyl-propylamino)-2-(2-piperidin-1-yl-ethyl-amino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.116 mL (0.815 mmol) of 2-piperidine-ethylamine in 0.03 mL of DMSO is heated at 80°C for 40 h, followed by the addition of 0.058 mL (0.407 mmol) of 2-piperidine-ethylamine after the first 20 h. The product is purified by autopreparative HPLC and after lyophilization gives 0.031 g of the resulting compound as a brown solid.

LC/MS system B: _Rt = 2.25 minutes, m/z = 516 MH+.

Example 19 (2S, 3S, 4R, 5R)-2-(3-Ethyl-[1,2,4]oxadiazol-5-yl)-5-[6-(1-ethyl-propyl-amino)-2-(2-morpholin-4-yl-ethylamino)-purin-9-yl]-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.070 g (0.161 mmol) of intermediate 9 and 0.106 mL (0.807 mmol) of 4-(2-aminoethyl)morpholine in 0.03 mL of DMSO is heated at 80°C for 26 hours, followed by the addition of 0.053 mL (0.403 mmol) of 4-(2-aminoethyl)morpholine after the first 6 hours. The product is purified by autopreparative HPLC and after lyophilization, 0.049 g of the resulting compound is obtained as a beige solid.

LC/MS system B: _Rt = 2.27 minutes, m/z = 532 MH+.

• 9

Example 20 (2S, 3S, 4R, 5R)-2-(3-Ethyl-[1,2,4]oxadiazol-5-yl)-5-[6-(1-ethyl-propyl-amino)-2-(2-piperidin-1-yl-ethyl-amino)-purin-9-yl]-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.070 g (0.161 mmol) of intermediate 9 and 0.115 mL (0.807 mmol) of 2-piperidine-ethylamine in 0.03 mL of DMSO was heated at 80°C for 40 h, followed by the addition of 0.057 mL (0.403 mmol) of 2-piperidine-ethylamine after the first 20 h. The product was purified by autopreparative HPLC and lyophilized to give 0.035 g of the resulting compound as a brown gum.

LC/MS system B: Rt = 2.33 minutes, m/z = 530 MH+.

Example 21 (2S, 3S, 4R, 5R)-2-(3-Ethyl-[1,2,4]oxadiazol-5-yl)-5-[6-(1-ethyl-propyl-amino)-2-(2-pyridin-2-yl-ethylamino)-purin-9-yl]-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.070 g (0.161 mmol) of intermediate 9 and 0.096 ml (0.807 mmol) of 2-(2-aminoethyl)pyridine in 0.03 ml of DMSO is heated at 80°C for 46 hours, followed by the addition of 0.096 ml (0.807 mmol) of 2-(2-aminoethyl)pyridine after the first 20 hours. The product is purified by autopreparative HPLC and after lyophilization, 0.035 g of the resulting compound is obtained as a beige solid.

LC/MS system B: _Rt = 2.38 minutes, m/z = 524 MH+.

Example 22 (2R, 3R, 4S, 5S)-2-[2-cyclopentyl-amino-6-(1-ethyl-propylamino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

A mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.08 mL (0.815 mmol) of cyclopentylamine in 0.03 mL of DMSO was heated at 80°C for 20 h in a sealed tube (e.g. Reactivial™). The product was purified by autopreparative HPLC and lyophilized to give 0.007 g of the title compound as a beige solid.

LC/MS system B: _Rt = 2.87 minutes, m/z = 472 MH+.

Example 23 (2R, 3R, 4S, 5S)-2-[2-cyclopentyl-amino-6-(1-ethyl-propylamino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

A mixture of 0.070 g (0.161 mmol) of intermediate 9 and 0.03 mL (0.807 mmol) of cyclopentylamine in 0.03 mL of DMSO was heated at 80°C for 20 h in a sealed tube (e.g. Reactivial™). The product was purified by autopreparative HPLC and lyophilized to give 0.008 g of the title compound as a creamy white solid.

LC/MS system B: _Rt = 3.01 minutes, m/z = 486 MH+.

Example 24 (2R, 3R, 4S, 5S)-2-[6-(1-Ethyl-propyl-amino)-2-(2S-hydroxy-cyclopentyl-(S)-yl-amino)-purin-9-yl]-5-(3-methyl-[1,2,4}-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

A mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.082 g (0.815 mmol) of (R,R)-aminocyclopentan-2-ol* in 0.03 mL of DMSO was heated at 80-95°C for 68 h in a sealed tube (e.g. Reactivial™). The product was purified by autopreparative HPLC and lyophilized to give 0.005 g of the title compound as a brown solid.

LC/MS system B: Rf = 2.57 minutes, m/z = 489 MH+.

* · · 9 9 · · · 9 9 99 999

9 9 9 9 9 • 9 9 9 9 9

99999 99 9 99 * · ·

L. E. Overman and S. Sugai, J. Org. Chem, 1985, 50, 4154

Example 25 (2S, 3S, 4R, 5R)-2-(3-Ethyl-[1,2,4]oxadiazol-5-yl)-5-[6-(1-ethyl-propyl-amino)-2-(2S-hydroxy-cyclopent-(S)-yl-amino)-purin-9-yl]-tetrahydro-furan-3,4-diol-formate

A mixture of 0.070 g (0.161 mmol) of intermediate 9 and 0.082 g (0.807 mmol) of (R,R)-aminocyclopentan-2-ol* in 0.03 mL of DMSO was heated at 80-95°C for 68 h in a sealed tube (e.g. Reactivial™). The product was purified by autopreparative HPLC and lyophilized to give 0.005 g of the title compound as a brown solid.

LC/MS system B: Rt = 2.68 minutes, m/z = 503 MH+.

* L. E. Overman and S. Sugai, J. Org. Chem, 1985, 50, 4154.

Example 26 (2R,3R,4S,5S)-2-[6-(1-Ethyl-propylamino)-2-(pyrrolidin-3R-yl-amino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.070 g (0.815 mmol) of (3R)-(+)-3-amino-pyrrolidine in 0.03 mL of DMSO was heated at 80°C for 6 h. The product was purified by autopreparative HPLC and lyophilized to give 0.041 g of the title compound as a creamy white solid.

LC/MS system B: Rt = 2.24 minutes, m/z = 474 MH+.

Example 27 (2S, 3S, 4R, 5R)-2-(3-ethyl-[1,2,4J-oxadiazol-5-yl)-5-[6-(1-ethyl74

-propyl-amino)-2-(pyrrolidin-3R-yl-amino)-purin-9-yl]-tetrahydrofuran-3,4-diol formate

A mixture of 0.070 g (0.161 mmol) of intermediate 9 and 0.07 g (0.807 mmol) of (3R)-(+)-3-aminopyrrolidine in 0.03 mL of DMSO was heated at 80°C for 6 h in a sealed tube (e.g. Reactivial™). The product was purified by autopreparative HPLC and lyophilized to give 0.041 g of the title compound as a creamy white solid.

LC/MS system B: _Rt = 2.31 minutes, m/z = 488 MH+.

Example 28 (2R, 3R, 4S, 5S)-2-[6-(1-Ethyl-propylamino)-2-(1S-hydroxymethyl-2-methyl-propylamino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-3,4-diol formate

A mixture of 0.069 g (0.163 mmol) of intermediate 11 and 0.084 g (0.815 mmol) of L-2-amino-3-methylbutanol in 0.03 mL of DMSO was heated at 80-95°C in a sealed tube (e.g. Reactivial™) for 5.5 days. The product was purified by autopreparative HPLC and lyophilized to give 0.030 g of the title compound as a yellow gum.

LC/MS system B: _Rt = 2.59 minutes, m/z = 491 MH+.

Example 29 (2R, 3R, 4S, 5S)-2-[2-(trans-4-amino-cyclohexyl-amino)-6-(1-ethyl-propyl-amino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

In a closed test tube (e.g. Reactivial™), a mixture of 0.070 g (0.161 mmol) is heated to 80-90°C for 66 hours

• »·

Β ·· Β intermediate 9 and 0.092 g (0.807 mmol) trans-1,4-diaminocyclohexane in 0.03 ml DMSO, followed by the addition of 0.092 mg (0.807 mmol) trans-1,4-diaminocyclohexane after the first 20 hours. The product was purified by autopreparative HPLC and lyophilization gave 0.082 g of the resulting compound as a brown solid. LC/MS system B: R _t = 2.21 minutes, m/z = 516 MH+.

Example 30 (2R, 3R, 4S, 5S)-2-[6-amino-2-(2-pyridin-2-yl-ethylamino)-purin-9-yl]-5-(3-methyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol diformate

In a sealed tube (e.g. Reactivial™), a mixture of 0.048 g of intermediate 17 and 0.06 ml of 2-(2-amino-ethyl)-pyridine in 0.05 ml of DMSO was heated at 90°C for 20 hours. 0.05 ml of 2-(2-amino-ethyl)-pyridine was added and the mixture was heated at 110°C for 16 hours. The residue formed was purified by autopreparative HPLC and after lyophilization, 0.0015 g of the resulting compound was obtained as a light brown solid.

LC/MS system B: _Rt =1.88 minutes, m/z =440 MH+.

Example 31 (2R,3R,4S,5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(2-morpholin-4-yl-ethyl-amino)-purin-9-yl]-5-(3-ethyl~[1,2,4]oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.034 g (0.062 mmol) of intermediate 4, 0.041 ml (0.31 mmol) of 4-(2-amino-ethyl)-morpholine and 0.03 ml of DMSO was heated at 80°C for 28 hours. The residue formed was purified by autopreparative HPLC and after lyophilization, 0.015 g of the resulting compound was obtained as a white solid.

LC/MS system A: _Rt = 3.67 minutes, m/z = 642MH+.

Example 32 (2R, 3R, 4S, 5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(2-piperidin-1-yl-ethyl-amino)-purin-9-yl]-5-(3-ethyl-[1,2,4J-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.034 g (0.062 mmol) of intermediate 4, 0.044 mL (0.311 mmol) of 2-piperidine-ethylamine in 0.03 mL of DMSO was heated at 80°C for 28 h. The residue formed was purified by autopreparative HPLC and after lyophilization, 0.010 g of the resulting compound was obtained as a white solid.

LC/MS system A: _Rt = 3.72 minutes, m/z = 640 MH ⁺ .

Example 33 (2R, 3R, 4S, 5S)-2-{6-(2,2-diphenyl-ethylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-propyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.075 g (0.135 mmol) of intermediate 23 and 0.085 g (0.67 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethylamine in 0.04 mL of diisopropylethylamine and 0.04 mL of DMSO was heated at 85°C for 40 h, followed by the addition of 0.085 g (0.677 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethylamine after the first 20 h. The product was purified by auto-preparative HPLC and lyophilization afforded 0.037 g of the title compound as a creamy white solid.

LC/MS system B: _Rt = 2.71 minutes, m/z = 651 MH+.

** • ♦ • ·

Example 34 (2R,3R,4S,5S)-2-{6-(2,2-diphenyl-ethylamino)-2-[2-(1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-methyl-[1,2,4]oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reactivial™), a mixture of 0.132 g (0.248 mmol) of intermediate 25 and 0.138 g (1.24 mmol) of histamine in 0.04 mL of diisopropylethylamine and 0.04 mL of DMSO was heated at 85-90°C for 40 h. The crude product formed was purified by autopreparative HPLC and after lyophilization, 0.032 g of the resulting compound was obtained as a creamy white solid.

LC/MS system B: _Rt = 2.59 minutes, m/z = 609 MH+.

Example 35 (2S, 3S, 4R, 5R)-2-(3-cyclopropyl-[1,2,4]-oxadiazol-5-yl)-5-[6-(1-ethyl-propylamino)-2-(2-piperidin-1-yl-ethylamino)-purin-9-yl]-tetrahydro-furan-3,4-diol-diformate

In a sealed tube (e.g. Reactivial™), a mixture of 70 mg (0.15 mmol) of intermediate 27 and 0.117 mL (0.83 mmol) of 2-piperidine-ethylamine in 0.3 mL of dimethylsulfoxide was heated at 90°C for 4 h. The crude product formed was purified by autopreparative HPLC and after lyophilization, 0.015 g of the resulting compound was obtained as a brown solid.

LC/MS system C: _Rt =2.32 minutes, m/z=542 MH+.

Example 36 (2S, 3S, 4R, 5R)-2-(3-cyclopropyl-[1,2,4]-oxadiazol-5-yl)-5-[6-(1-ethyl-propylamino)-2-(2-morpholin-4-yl-ethylamino)-purin-9-yl]-tetrahydro-furan-3,4-diol-diformate

The resulting compound of Example 36 is prepared according to the procedure

• · · · ♦ ··· ··· ··· ··· ··· ··· ·«· Example 35 using 0.108 ml (0.825 mmol) of 4-(2-aminoethyl)morpholine, which is heated at 90°C for 4 hours. After lyophilization, 0.009 g of the resulting compound is obtained as a brown solid.

LC/MS system C: _Rt =2.32 minutes, m/z=544 MH+.

Example 37 (2S, 3S, 4R, 5R)-2-(3-cyclopropyl-[1,2,4]-oxadiazol-5-yl)-5-[6-(1-ethyl-propyl-amino)-2-(2-(2-pyridinyl)-ethylamino)-purin-9-yl]-tetrahydro-furan-3,4-diol-diformate

The resulting compound of Example 37 was prepared according to the procedure of Example 35 using 0.104 g (0.825 mmol) of 2-(2-aminoethyl)pyridine which was heated at 90°C for 4 hours. After lyophilization, 0.012 g of the resulting compound was obtained as a brown solid.

LC/MS system C: _Rt =2.18 minutes, m/z=535 MH+.

Example 38 (2S, 3S, 4R, 5R)-2-(3-cyclopropyl-[1,2,4]oxadiazol-5-yl)-5-{6-(1-ethyl-propyl-amino)-2-(2-(1-methyl-1H-imidazol-4-yl)-ethylamino)-purin-9-yl]-tetrahydrofuran-3,4-diol diformate

The resulting compound of Example 38 was prepared according to the procedure of Example 35 using 0.14 g (0.825 mmol) of 2-(1-methyl-1H-imidazol-4-yl)-ethylamine, prepared from the corresponding bishydrochloride by neutralization by adding a small amount of solid sodium hydroxide in methanol and evaporating the volatile fraction under a stream of nitrogen for 4 hours at 90° C. After lyophilization, 0.015 g of the resulting compound was obtained as a brown solid.

9 9 9 9 9

9 9 9 9

9 99 99 ·

LC/MS system C: Rt = 2.32 minutes, m/z-542 MH+

Example 39 (2R, 3R, 4S, 5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(2-pyrrolidin-1-yl-ethyl-amino)-purin-9-yl]-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol diformate

A mixture of 70 mg (0.15 mmol) of intermediate 3 and 0.114 g (1 mmol) of 1-(2-aminoethyl)pyrrolidine in 0.2 ml of dimethyl sulfoxide is heated to 90°C in a sealed tube (e.g. Reactivial™) for 4 hours with constant stirring. The crude product formed is purified by autopreparative HPLC. After lyophilization, 0.008 g of the resulting compound is obtained as a brown solid.

LC/MS system B: Rt = 2.67 minutes, m/z = 626 MH+.

Example 40 (2R, 3R, 4S, 5S)-2-{6-(2,2-diphenyl-ethylamino)-2-[2-pyridin-2-yl-amino)-ethylamino]-purin-9-yl}-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol diformate

The resulting compound of Example 40 was prepared in a similar manner to the resulting compound of Example 39 using 0.137 g (1 mmol) of intermediate 37 and 4 hours at 90° C. After lyophilization, 0.003 g of the resulting compound was obtained as a brown solid.

LC/MS system A: RT 2.74 minutes, m/z=649 MH+.

Example 41 (2R,3R,4S,5S)-2-{2-(bicyclo-[2,2,1]hept-2-yl-amino)-6-(2,2-diphenyl-ethyl-amino)-purin-9-yl}-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)tetrahydro-furan-3,4-diol-formate

44 · 44 ♦ · ♦ · ♦ · 4 4 4

4 4 4 · ·

4 4 4*4

444 44 444 44 4*4

The resulting compound of Example 41 was prepared in a similar manner to the resulting compound of Example 39 using 0.110 g (1 mmol) of (±)-exo-2-amino-norbornane and 4 hours at 90° C. After lyophilization, 0.008 g of the resulting compound was obtained as a brown solid.

LC/MS system B: Rt=3.77 minutes, m/z=623 MH+.

Example 42 (2R, 3R, 4S, 5S)-2-{2-(2-[3,4-dimethoxy-phenyl]-ethylamino)-6-(2,2-diphenyl-ethylamino)-purin-9-yl}-5-(3-ethyl-[1,2,4-yoxadiazol-5-yl)-tetrahydrofuran-3,4-diol-formiate

The resulting compound of Example 42 was prepared in a similar manner to the resulting compound of Example 39 using 0.181 (1 mmol) of 2-(3,4-dimethoxy-phenyl)-ethylamine and 4 hours at 90° C. After lyophilization, 0.002 g of the resulting compound was obtained as a brown solid.

LC/MS system B: RT 3.42 minutes, m/z=693 MH+.

Example 43 (2R, 3R, 4S, 5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(2-hydroxy-ethylamino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydrofuran-[3,4-d]-diol formate

The resulting compound of Example 43 was prepared in a similar manner to the resulting compound of Example 39 using 0.061 g (1 mmol) of 2-hydroxyethylamine and 4 hours at 90°C. After lyophilization, 0.013 g of the resulting compound was obtained as a brown solid. LC/MS system B: Rt 3.02 minutes, m/z=573 MH+.

• ·· • · · •» 0 • 0 · · 99 9 4 9 9 * · 0 · 4 4 · • 9 · · · · 00 449 94 4 9

Example 44 (2R, 3R, 4S, 5S)-2-[6-(2,2-diphenyl-ethylamino)-2-(4-fluoro-phenyl-amino)-purin-9-yl]-5-(3-ethyl-[1,2,4]-oxadiazol-5-yl)-tetrahydro-furan-3,4-diol-formate

In a sealed tube (e.g. Reacti-vial™), a mixture of 50 mg (0.09 mmol) of intermediate 3 and 0.11 g (1 mmol) of 4-fluoroaniline in 0.2 ml of DMSO is heated with constant stirring to 90°C for 20 hours, and then to 110°C for 20 hours. The resulting crude product is purified by autopreparative HPLC and lyophilized to give 0.005 g of the resulting compound as a brown solid.

LC/MS system C: Rt=3.60 minutes, m/z=623 MH+.

Example 45 (2R, 3R, 4S, 5S)-2-[2-(1-Benzyl-pyrrolidin-3S-yl-amino)-6-(2,2-diphenyl-ethyl-amino)-purin-9-yl]-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol diformate

The resulting compound of Example 45 was prepared in a similar manner to the resulting compound of Example 39 using 0.18 g (1 mmol) of 1-benzyl-3S-amino-pyrrolidine and 4 hours at 90° C. After lyophilization, 0.003 g of the resulting compound was obtained as a brown solid.

LC/MS system C: Rt=2.75 minutes, m/z=688 MH+.

Example 46 (2R,3R,4S,5S)-2-{6-phenethyl-amino-2-[2-1-methyl-1H-imidazol-4-yl)-ethyl-amino]-purin-9-yl}-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol diformate

In 3 ml of a solution of DCM and tetrahydrofuran in a ratio of 9:1, dissolve ·· A AA

AAAA A A

AAA A A

AAA A«AA AAA A A

AA AAA AA using ultrasonic sonication of 0.083 mg (0.15 mmol) of intermediate 34. Under constant stirring, 0.057 ml (3.32 mmol) of N,N-diisopropylethylamine and 0.021 ml (0.16 mmol) of trimethylacetyl chloride were added to the reaction mixture at 0°C under nitrogen. The reaction mixture was allowed to warm to room temperature over 2 hours, cooled again to 0°C, and a solution of 0.015 g (0.18 mmol) of N-hydroxypropionamidine in 0.5 ml of tetrahydrofuran was added under constant stirring. The reaction mixture was warmed to room temperature and stirred for 16 hours. The solvent was evaporated in vacuo and the reaction mixture was dissolved in 10 ml of toluene. The reaction mixture was heated to reflux temperature (120°C) for 8 hours. The product was purified on a Varian Mega Bond Elut column (5 g Si, size 20 ml) eluting with ethyl acetate in methanol in a ratio of 50:1 to 1:1 to give 0.01 g of crude product as a yellow oil. The product was dissolved in 4 ml of a mixture of trifluoroacetic acid and water in a ratio of 9:1 at 0°C and nitrogen atmosphere over 4 hours with constant stirring. The solvent was evaporated in vacuo, 50 ml of toluene were azeotropically distilled twice and the residue was purified by autopreparative HPLC. 0.004 g of the resulting compound was obtained as a yellow gum.

LC/MS system C: Rt=2.39 min m/z=561 MH+

Example 47 (2R, 3R, 4S, 5S)-2-{6-(2-cyclohexyl-ethylamino)-2-[2-(1-methyl-1H-imid-azol-4-yl)-ethylamino]-purin-9-yl}-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diol diformate

The resulting compound of Example 47 was prepared in a similar manner to the resulting compound of Example 46 using 0.081 g (0.146 mmol) of intermediate 35, 0.02 ml (0.16 mmol) of trimethylacetyl chloride, 0.056 ml (0.32 mmol) of N,N-diisopropylethylamine in 2 ml of a mixture of DCM and tetrahydrofuran.

4

4 44 • 4

4

4 4 4 44

4 4

4« 444 in a ratio of 9:1 and 0.014 g (0.175 mmol) N-hydroxy-propion-amidine. Purification by autopreparative HPLC afforded 0.003 g of the resulting compound as a yellow gum.

LC/MS system C: Rt=2.54 minutes, m/z=567 MH+.

Example 48 (2R, 3R, 4S, 5S)-2-{6-(3,3-dimethyl-butylamino)-2-[2-(1-methyl-1H-imidazol-4-yl)-ethylamino]-purin-9-yl}-5-(3-ethyl-[1,2,4]oxadiazol-5-yl)-tetrahydrofuran-3,4-diiodiformate

The resulting compound of Example 48 was prepared in a similar manner to the resulting compound of Example 46 using 0.05 g (0.09 mmol) of intermediate 36, 0.012 mL (0.1 mmol) of trimethylacetyl chloride, 0.035 mL (0.2 mmol) of N,N-diisopropylethylamine in 2 mL of a 9:1 mixture of DCM and tetrahydrofuran and 0.0087 g (0.11 mmol) of N-hydroxy-propionamidine. Purification by autopreparative HPLC gave 0.002 g of the resulting compound as a yellow gum.

LC/MS system C: Rt=2.42 minutes, m/z=541 MH+.

Biological monitoring

The results of monitoring the agonist effect on receptors of types A2a, A3 and A1 (according to the described procedure 1) are summarized in the following table:

Example n: A2a A3 A1 1 1.19 >197 1306 2 0.64 > 197 1823 3 4.63 >304 6719

4 5.37 >383 >=3996 5 6.12 >309 1391.2 6* 41.35 >642 >4833 7* 11.02 >117 1013.4 8* 14.05 >215 >=3865 9* 0.81 >231 1692.4 9** 0.086 >287 3006 10* 7.66 >269 3449.6 11* 6.66 >266 145.5 12* 4.54 >302 1863.5 13 0.61 >289 >=4370 14 0.66 >239 >4587 15 2.29 >130 >5511 16* 11.87 >362 >6244 17* 3.97 >362 >6244 18* 8.16 >314 >6244 19* 34.52 >694 >5860 20* 17.08 >694 >=1853 21* 9.39 >303 >5090 22 22.25 >193 78.28 23 12.72 >163 17.02 24 18.13 >284 >5264 25 19.35 >163 515.35 26* 5.18 >284 >5264

44 4 ·« 4 4 44

4 4 4

4 4 4 4 < 4 4 4

444 44 444

27* 10.5 >284 263.14 28* 5.49 >284 >5263 29* 8.92 >117 989.5 30* 19.54 >215 1460.7 31 30.6 >262 6452 32 31.4 >258 7521 33* 8.35 >259 >815.9 34* 8.31 231.1 3270.8 35 7.89 >194 912.1 36 20.13 >194 >9364 37 49.45 >87 >10402 38 2.02 >87 670.04 39 30.21 >130 4505.4 40 4.89 >130 >=3311.7 41 23.93 >130 2033.2 42 32.77 >130 >6064 43 6.85 >130 1367.6 44 94.39 >165 >6131 45 29.82 >165 >3738.84 46 0.90 >165 3560.13 47 6.93 >165 4993.28 48 4.40 >165 16.84

* Data are minimum values, as the presence of inactive impurities was found after testing.

** Results of retested purified compounds.

The values given in the table are EC50 values as a ratio of NECA.

Abbreviations used

TMS trimethylsilyl TFA trifluoroacetic acid DMF N,N-dimethylformamide NOTHING N-ethylcarboxamide-adenosine DMAP 4-dimethylaminopyridine PACE 2,2,6,6-tetramethyl-1-piperidinyloxy (free radical) TMSOTf trimethylsilyl trifluoromethyl sulfonate DBU 1,8-diazabicyclo[5,4,0Jundec-7-ene BSA bistrimethylsilylacetamide DCM dichloromethane DAST diethylamino-sulfur-trifluoride Ph phenyl CDI carbonyldiimidazole EEDQ 2-ethoxy-1-ethoxy-carbonyl-1,2 dihydroquinone NSAIDs nonsteroidal anti-inflammatory drugs DMSO dimethyl sulfoxide Me methyl Et ethyl THF tetrahydrofuran

ρ &&

Claims (29)

PATENT CLAIMS i. 2- (Purin-9-yl) -tetrahydrofuran-3,4'-diol derivatives of general formula (1): wherein R ¹ and R ² independently represent a group selected from the following: 1 / C ₃ -8cykloalkyl-; 2 / hydrogen; 3 / aryl ₂ CHCH ₂ -; 4 / C3-8cycloalkylC1-6alkyl-; 5 / Ci. ₈ alkyl-; 6 / arylC _1-6 alkyl-; 7 / R ⁴ R ⁵ N-Ci. ₆ alkyl-; 8 / Ci. ₆ alkyl-CH (CH ₂ OH) -; 9 / arylC 1-5 alkyl-CH (CH ₂ OH) -; 10) arylC _1-5 alkyl-C (CH ₂ OH) 2 -; 11 / C 3 -cycloalkyl independently substituted with one or more (CH 2) p R ⁶ groups; 12 / H ₂ NC (= NH) NHC ₁ . 13 / group of formula, < ^CH 2 \ 7 (CH ₂ ) _b 9 9 • • 9999 • 9 • 9 9 9 9 9 9 9 9 • 9 9 9 9 Or a group in which one carbon atom of the methylene adjacent to X, or both, if any, is replaced by methyl; 14 C 1 -C 6 -alkyl-OH; C 1 -C 6 -halaloalkyl; 16 / group of formula (CH ₂ ) _c CO (CH ₂ ) -? NR ⁷ 17) aryl a 18 / - _(CH2) fSO2NHg (C 4 alkyl-) ₂ -g or - (CH ₂₎ FSO ₂ NHG (arylC _1.4 alkyl) _{2. g} ; R ³ denotes methyl, ethyl, -CH = CH ₂ , n-propyl, -CH ₂ CH = CH ₂ ,> CH = CHCH 3, isopropenyl, cyclopropyl, cyclopropenyl, -CH (OH) CH ₃ , - (CH ₂ ) halogen , - (CH ₂ ) h Y (CH ₂ ) 1 H, -COO (CH ₂ ), H, -CON (CH ₂ ) _m H ((CH ₂ ) _n H), -CO (CH ₂ ) _o H or - ( (CH ₂ ) _for H) = NO (CH ₂ ) _in H Y denotes O, S or N (CH ₂ ) ₃ H; a and b are independently an integer from 0 to 4, wherein a + b is from 3 to 5; c, d and e independently denote an integer from 0 to 3, wherein c + d + e is in the range from 2 to 3; f denotes 2 or 3 and g denotes an integer from 0 to 2; p denotes 0 or 1; q denotes 1 or 2; h denotes 1 or 2; i denotes an integer from 0 to 1, wherein h + i is from 1 to 2; j denotes an integer from 0 to 1, wherein h + i + j ranges from 1 to 2; I denotes 1 or 2; m and n independently represent an integer from 0 to 2, wherein m + n is in the range from 0 to 2; o denotes an integer from 0 to 2; u and v independently denote 0 or 1, wherein u + v is an integer ranging from 0 to 1; R ⁴ and R ⁵ independently represent hydrogen, C _1-6 alkyl, aryl, arylC 1-6 alkyl or NR ⁴ R ⁵ together denote pyridinyl, pyrrolidinyl, piperidinyl, morpholinyl, azetidinyl, azepinyl, piperazinyl or N-C 1-6 -alkyl-piperazinyl; R ⁶ denotes OH, NH ₂ , NHCOCH 3 or halogen; R ⁷ denotes hydrogen, O-alkyl, C _1-6 alkyaryl or COC 1-6 alkyl; X denotes NR ⁷ , O, S, SO or SO ₂ ; and salts or solvates thereof. A compound of formula I according to claim 1, wherein R ³ denotes methyl, ethyl, n-propyl, cyclopropyl or -CH ₂ OH. A compound of formula I according to claim 2, wherein R ³ denotes methyl, ethyl or n-propyl. A compound of formula I according to claim 2, wherein R ³ denotes ethyl. A compound of formula (I) according to any one of claims 1 to 4, wherein R ¹ and R ² together are not hydrogen. A compound of formula I according to one of claims 1 to 5, wherein R ¹ denotes C 1. ₈ alkyl, Cs.scykloalkylCvealkyl-, arylC 6alkylnebo hydrogen. A compound of formula I according to one of claims 1 to 5, wherein R ¹ denotes aryl ₂ CHCH ₂ -. A compound of formula 1 according to claim 6 wherein R ¹ denotes -CH (CH ₂ CH ₃ ) ₂ , phenylethyl, cyclohexylethyl, - (CH ₂ ) ₂ C (CH ₃ ) ₃ or hydrogen. Compound of formula I according to one of claims 1 to 5, wherein R ¹ denotes Ph ₂ CHCH ₂ -, -CH (CH ₂ CH ₃ ) ₂ , hydrogen or phenylethyl-. A compound of formula I according to claim 7, wherein R ¹ denotes Ph ₂ CHCH ₂ -. Compound of formula I according to one of Claims 1 to 11 10. wherein R ² denotes -CH (CH ₂ OH) C _1-6 alkyl, 4-aminocyclohexyl, pyrrolidinyl or arylCH ₂ CH ₂ . A compound of formula (I) according to one of claims 1 to 10, wherein R ² denotes pyrrolidin-3-yl N-substituted with C 1-6 alkyl or benzyl, R ⁴ R ⁵ NC ₁ . ₆ alkyl, Ci-6 alkyl-OH, aryl, arylC. ₅ alkyl-CH _(CH2 OH) -, C ₃ -8cykloalkyl, aryl (CH ₂₎ 2 or C ₃ -8cykloalkyl independently substituted with one or more - (CH _{2) p} R ^6th A compound of formula I according to claim 12, wherein R denotes 2- (1H-imidazol-4-yl) -ethyl, morpholin-1-yl-ethyl, pyrrolidin-1-yl-ethyl, pyridin-2-yl- amino-ethyl, (+) - exonorborn-2-yl, 3,4-dimethoxy-phenylethyl, 2-hydroxy-ethyl, 4-fluorophenyl, N-benzyl-pyrrolidin-3-yl, pyridine- 2-yl-ethyl, 1S-hydroxy-methyl-2-phenyl-ethyl, -cyclopentyl, phenylethyl, piperidin-1-yl-ethyl or 2-hydroxy-pentyl. A compound of formula I according to claim 11, wherein R ² denotes -CH (CH ₂ OH) CH (CH ₃ ) ₂ , trans -4-aminocyclohexyl, 2- (1-methyl-1H-imidazol-4-yl) ) CH ₂ CH ₂ - or pyrrolidin-3-yl. Compound of formula (I) according to one of claims 1 to 10, wherein R ² denotes 2- (1-methyl-1H-imidazol-4-yl) CH ₂ CH ₂ -, 1S-hydroxymethyl-2-phenylethyl, phenylethyl or 1S-hydroxymethyl-2-methylpropyl. A compound of formula (I) according to one of claims 1 to 15, wherein R ⁴ and R ⁵ independently represent hydrogen, C 1-6 alkyl, aryl, arylC 1-6 alkyl- or NR ⁴ R ⁵ together represent pyrrolidinyl, piperidinyl, morpholinyl, azetidinyl, azepinyl, piperazinyl or NC 1-6 alkyl-piperazinyl. A compound of formula I according to claim 16, wherein R ⁴ and R ⁵ independently represent hydrogen, aryl or NR ⁴ R ⁵ together represent pyrrolidinyl, piperidinyl, morpholinyl, azetidinyl, azepinyl, piperazinyl or N-methylpiperazinyl. A compound of formula I according to claim 1 which is (2R, 3R, 4S, 5S) -2- {6- (2,2-diphenylethylamino) -2- [2- (1-methyl-1H-imidazole) -4-yl) -ethyl-amino] -purin-9-yl} -5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol or its salts and solvates. A compound of formula I according to claim 1 which is (2R, 3R, 4S, 5S) -2- [6-amino-2- (1S-hydroxymethyl-2-phenyl-ethylamino) -purin-9-yl] - 5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol or its salts and solvates. Compounds of formula I according to claim 1 which are: (2R, 3R, 4S, 5S) -2- {6- (2,2-diphenyl-ethylamino) -2- [2- (1-methyl-1H-imidazol-4-yl) ethylamino] -purin-9- yl} -5- (3-methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (2,2-Diphenyl-ethylamino) -2- (pyrrolidin-3R-ylamino) -purin-9-yl] -5- (3-ethyl) - [1,2,4] oxadiazol-5-yl) -tetrahydro92 -furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [2- (trans-4-amino-cyclohexylamino) -6- (2,2-diphenyl-ethylamino) -purin-9-yl] -5- (3 -ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (2,2-Diphenyl-ethylamino) -2- (1S-hydroxy-methyl-2-methyl-propylamino) -purin-9-yl] -5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (1-ethyl-propylamino) -2- (2-morpholin-4-yl-ethylamino) -purin-9-yl] -5- (3 -methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- {6-Amino-2- [2- (1-methyl-1H-imidazol-4-yl) -ethylamino] -purin-9-yl} -5- ( 3-methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6-amino-2- (2-pyridin-2-yl-ethylamino) -purin-9-yl] -5- (3-ethyl- [1,2, 4] -oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- {6-amino-2- [2- (1-methyl-1 H -imidazol-4-yl) -ethylamino] -purin-9-yl} -5- (3 -ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- (6-Amino-2-cyclopentyl-amino-purin-9-yl) -5- (3-methyl- [1,2,4] oxadiazol-5-yl) 1-tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- [6-amino-2- (1S-hydroxymethyl-2-phenyl-ethylamino) -purin-9-yl] -5- (3-methyl- [1,2, 4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-ethyl- [1,2,4] oxadiazol-5-yl) -5- {6- (1-ethyl-propylamino) -2- [2] - (1-Methyl-1H-imidazol-4-yl) -ethylamino] -purin-9-yl} -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- {6- (1-ethyl-propylamino) -2- [2- (1-methyl-1 H -imidazol-4-yl) -ethylamino] -purin-9-yl } -5- {3-Methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- (6-Amino-2-phenethylamino-piirin-9-yl) -5- (3-methyl- [1,2,4] oxadiazol-5-yl) 1-Tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [2- (trans-4-amino-cyclohexyl-amino) -6- (1-ethyl-propylamino) -purin-9-yl] -5- (3-methyl) [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (1-ethyl-propylamino) -2- (1S-hydroxymethyl-2-phenyl-ethylamino) -purin-9-yl] -5- (3 -methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (1-ethyl-propylamino) -2- (2-piperidin-1-yl-ethylamino) -purin-9-yl] -5- (3-Methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-ethyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1-ethyl-propylamino) -2- (2 morpholin-4-yl-ethylamino) -purin-9-yl] -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-ethyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1-ethyl-propylamino) -2- (2 -piperidin-1-yl-ethylamino) -purin-9-yl] -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-ethyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1-ethyl-propylamino) -2- (2 -pyridin-2-yl-ethylamino) -purin-9-yl] -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [2-Cyclopentyl-amino-6- (1-ethyl-propylamino) -purin-9-yl] -5- (3-methyl- [1,2,4] -oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [2-Cyclopentyl-amino-6- (1-ethyl-propylamino) -purin-9-yl] -5- (3-ethyl- [1,2,4] - oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (1-ethyl-propylamino) -2- (2S-hydroxy-cyclopent- (S) -yl-amino) -purin-9-yl] -5- (3-Methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-ethyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1-ethyl-propylamino) -2- (2S) -hydroxy-cyclopent- (S) -yl-amino) -purin-9-yl] -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (1-ethyl-propylamino) -2- (pyrrolidin-3R-ylamino) -purin-9-yl] -5- (3-methyl- [ 1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-ethyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1-ethyl-propylamino) -2- (pyrrolidine) 3R-yl-amino) -purin-9-yl] -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (1-ethyl-propylamino) -2- (1S-hydroxymethyl-2-methyl-propylamino) -purin-9-yl] -5- (3 -methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [2- (trans-4-amino-cyclohexylamino) -6- (1-ethyl-propylamino) -purin-9-yl] -5- (3-ethyl) [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6-amino-2- (2-pyridin-2-yl-ethylamino) -purin-9-yl] -5- (3-methyl- [1,2, 4] -oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (2,2-Diphenyl-ethylamino) -2- (2-morpholin-4-yl-ethylamino) -purin-9-yl] -5- (3-Ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- {6- (2,2-Diphenyl-ethylamino) -2- (2-piperidin-1-yl-ethyl-amino) -purin-9-yl] -5- (3-Ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 53) -2- (6- (2,2-Diphenyl-ethylamino) -2- [2- (1-methyl-1H-imidazol-4-yl) ethylamino] -purin-9 -yl} -5- (3-propyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- {6- (2,2-Diphenyl-ethylamino) -2- [2- (1H-imidazol-4-yl) -ethylamino] -purin-9-yl} - 5- (3-Methyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- {3-Cyclopropyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1-ethyl-propylamino) -2- ( 2-piperidin-1-yl-ethylamino) -purin-9-yl-tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-Cyclopropyl- [1,2,4] oxadiazol-5-yl) -5- [6- ( ^1H -ethyl-propylamino) -2- (2-Morpholin-4-yl-ethylamino) -purin-9-yl] - -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-Cyclopropyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1'-ethyl-propylamino) -2- (2- (2-Pyridinyl) -ethylamino) -purin-9-yl] -tetrahydro-furan-3,4-diol; (2S, 3S, 4R, 5R) -2- (3-cyclopropyl- [1,2,4] oxadiazol-5-yl) -5- [6- (1-ethyl-propylamino) -2- (2 - (1-methyl-1H-imidazol-4-yl) -ethylamino) -purin-9-yl) -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (2,2-diphenyl-ethylamino) -2- (2-pyrrolidin-1-yl-ethylamino) purin-9-yl] -5- (3- ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- {6- (2,2-Diphenyl-ethylamino) -2- [2- (pyridin-2-ylamino) -ethylamino] -purin-9-yl} - 5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- (2- (bicyclo [2.2.1] hept-2-ylamino) -6- (2,2-diphenyl-ethylamino) purine-9- yl} -5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- {2- (2- [3,4-dimethoxy-phenyl] -ethylamino) -6- (2,2-diphenyl-ethylamino) -purin-9-yl} - 5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (2,2-Diphenyl-ethylamino) -2- (2-hydroxy-ethyl-amino) -purin-9-yl] -5- (3-ethyl) [1,2,4] oxadiazol-5-yl) -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- [6- (2,2-diphenyl-ethylamino) -2- (4-fluoro-phenylamino) -purin-9-yl] -5- (3-ethyl) [1,2,4] oxadiazol-5-yl) -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- [2- (1-benzyl-pyrrolidin-3S-yl-amino) -6- (2,2-diphenyl-ethylamino) - Purin-9-yl] -5- {3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydrofuran-3,4-diol; (2R, 3R, 4S, 5S) -2- {6-Phenethylamino-2- [2- (1-methyl-1H-imidazol-4-yl) -ethylamino] -purin-9-yl} -5 - (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- {6- (2-Cyclohexyl-ethylamino) -2- [2- (1-methyl-1H-imidazol-4-yl) -ethylamino] -purin-9- yl} -5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; (2R, 3R, 4S, 5S) -2- {6- (3,3-Dimethyl-butylamino) -2- [2- (1-methyl-1H-imidazol-4-yl) ethylamino] -purine- 9-yl} -5- (3-ethyl- [1,2,4] oxadiazol-5-yl) -tetrahydro-furan-3,4-diol; or salts and solvates thereof. 21. A pharmaceutical composition comprising a compound of the formula I as claimed in any one of claims 1 to 20, or a pharmaceutically acceptable salt or solvate thereof, in admixture with one or more pharmaceutically acceptable diluents or carriers. A compound of formula (I) according to claims 1 to 20 or a salt or solvate thereof for use in pharmacy. Use of a compound of formula I according to claims 1 to 20 or a pharmaceutically acceptable salt or solvate thereof for the manufacture of a medicament for the treatment of inflammatory diseases such as asthma or chronic bronchial obstruction (COPD). 24. A method for the treatment or prophylaxis of an inflammatory disease (asthma or chronic bronchial obstruction), comprising administering to a patient an effective amount of a compound of formula (I) according to claims 1 to 20, or a pharmaceutically acceptable salt or solvate thereof. • · A process for preparing a compound of formula I according to claims 1 to 20, characterized in that: a) reacting a compound of formula II wherein: R ¹ is as defined in claims 1, 5 to 10 and 18 to 20; R ³ is as defined in claims 1 to 4 and 18 to 20 and L denotes a leaving group - halogen (chlorine) or a derivative thereof protected with a compound of formula R ² NH ₂ or a protected derivative thereof, wherein R ² is as defined in claims 1, 5, 11 to 15 and 18 to 20. b) reacting a compound of formula VI wherein: R ¹ is as defined in claims 1, 5 to 10 and 18 to 20; R ² is determined by the claims 1, 5, 11-15 and 18-20, or a protected derivative compound • 4 44 4 4 · 4 4 4 43 4 With a carboxylic activating agent or an amidoxime compound of the formula OH-N = C (R ³ ) NH ₂ , wherein R ³ is as defined in claims 1 to 4 and 18 to 20; c) reacting a compound of formula IX (ix) wherein: R ¹ is as defined in claims 1, 5 to 10 and 18 to 20; R ² is as defined in claims 1, 5, 11 to 15 and 18 to 20 with a compound of formula X (X) wherein: R ³ is as defined in claims 1 to 4 and 18 to 20 and L denotes a leaving group or a protected derivative thereof. d) cleavage of the protecting group attached to the compound of formula I and optionally converting the compound of formula I or a salt thereof into another salt thereof. • · A process for the preparation of a compound of formula I according to claims 1 to 20, characterized in that: a) reacting a compound of formula IIa wherein: R ² is as defined in claims 1, 5, 11 to 15 and 18 to 20; R ³ is as defined in claims 1 to 4 and 18 to 20 and L denotes a leaving group (chlorine) or a protected derivative thereof with a compound of formula R ¹ NH 2, wherein R ¹ is as defined in claims 1, 5 to 10 and 18 to 20; or be b) prepare a compound of formula I wherein R ¹ is hydrogen by converting a compound of formula IIb O HO (lib) OH 100 wherein: R ² is as defined by claims 1.5, 11 to 15 and 18 to 20 R ³ is as defined by claims 1 to 4 and 18 to 20. A compound of formula II wherein: R ¹ is as defined in claims 1, 5 to 10 and 18 to 20; R ³ is as defined in claims 1 to 4 and 18 to 20 and L denotes a leaving group or a derivative thereof with a bonded protecting group. A compound of formula V wherein: R ³ is as defined in claims 1 to 4 and 18 to 20 and L ¹ and L ² denote a leaving group or a protected derivative thereof. 101 A compound of formula X (X) wherein R ³ is as defined in claims 1 to 4 and 18 to 20 and L denotes a leaving group or a protected derivative thereof.