JPH10182576A - Azidohalogenbenozyl derivative, saccharide compound and protection of hydroxyl group - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject new compound, excellent in heat resistance, capable of introducing a protecting group of hydroxyl group capable of being deprotected under mild conditions and useful for protecting hydroxyl group in various compounds having the hydroxyl group, especially the hydroxyl group of a sacccharide and a derivative thereof. SOLUTION: This compound is represented by formula I (A is a halogen; B is a halogen or H; X is a group reactive with hydroxyl group), e.g. 4-azido-3- chlorotoluene. The compound represented by formula I in which V is a halogen is obtained by treating an aminohalogenotoluene represented by formula II with sodium nitrite in an aqueous solution of hydrochloric acid, thereby providing an azidohalogenotoluene and further reacting the resultant azidohalogenotoluene with an N-halogenosuccinimide in the presence of a catalyst such as 2,2'-azobisisobutyronitrile in a suitable solvent, as necessary, in an inert gas stream under shielded light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to various compounds having a hydroxyl group, and more particularly to a novel azidohalogenobenzyl derivative useful for protecting the hydroxyl group of sugars and sugar derivatives, and more particularly, to a compound having excellent acid resistance and mild conditions. The present invention relates to a novel azidohalogenobenzyl derivative capable of introducing a hydroxyl-protecting group that can be deprotected. The present invention also relates to a sugar compound protected using the derivative, and a method for protecting a hydroxyl group using the derivative.

[0002]

2. Description of the Related Art In a reaction using a compound having a hydroxyl group, particularly in the synthesis of a sugar chain,
Since the sugars and derivatives thereof used have many other hydroxyl groups not involved in the formation of the desired bond, it is necessary to protect these hydroxyl groups with protecting groups and exclude them from the sugar chain elongation reaction system. On the other hand, a specific hydroxyl-protecting group involved in sugar chain binding must be sequentially eliminated to function as an acceptor. That is, for example, in elongation synthesis of a sugar chain, a specific protecting group is bonded to a specific hydroxyl group in advance so that cleavage can be performed when necessary, and selective cleavage and bonding to a new sugar to be added are repeated respectively. In addition to the property that these protecting groups can be selectively removed as necessary, it is essential that these protecting groups be stable under various conditions such as a glycosidic bond forming reaction and a cleavage reaction of other protecting groups. Among them, Lewis acids and the like are used for glycosidation, and especially in automatic synthesis such as solid phase synthesis, since they are continuously placed in an acidic environment, the protecting groups used need to have excellent acid resistance. Become. In particular, in the automatic synthesis of a sugar chain, elimination of a protecting group must be performed under relatively mild conditions such as temperature and pH. Conventional protecting groups for hydroxyl groups such as p-methoxybenzyl group and p-azidobenzyl group can be eliminated under relatively mild conditions,
Although there is no problem in this respect, the acid resistance is poor, and it has been extremely difficult to efficiently synthesize a sugar chain using these protecting groups, in particular, a sugar chain having a side chain. In view of the above situation, a protective group for a hydroxyl group has been developed.However, a sufficient protective group for a hydroxyl group which is excellent in acid resistance and which is eliminated under mild conditions has not yet been obtained. Absent.

The present invention is applicable not only to ordinary protection of hydroxyl groups but also to conventional solid-phase synthesis of sugar chains using an automatic synthesizer as well as conventional synthesis of sugar chains in a liquid phase. It is an object of the present invention to provide a novel derivative which can introduce the protecting group into a hydroxyl group-containing compound. Another object of the present invention is to provide a sugar compound protected using the derivative, and a method for protecting a hydroxyl group using the derivative.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, have found that the protecting group for the hydroxyl group obtained by using the azidohalogenobenzyl derivative represented by the following general formula (I) has been developed. The present invention has been found to have excellent acid resistance, can be rapidly desorbed under mild conditions, and can be applied to a continuous solid-phase synthesis method of sugar chains using an automatic synthesizer, and have completed the present invention. Was.

That is, the present invention is as follows. (1) General formula (I)

[0006]

Embedded image

Wherein A represents a halogen atom, B represents a halogen atom or a hydrogen atom, and X represents a group capable of reacting with a hydroxyl group (hereinafter referred to as an azidohalogenobenzyl derivative). I)].

(2) The azidohalogenobenzyl derivative according to (1), wherein in formula (I), X represents a halogen atom or an imidoyloxy group.

(3) The azidohalogenobenzyl derivative according to (1), wherein in formula (I), B represents a hydrogen atom and X represents a halogen atom.

(4) The azidohalogenobenzyl derivative according to (1), which is 4-azido-3-chlorobenzyl bromide.

(5) At least one hydrogen atom of a hydroxyl group has the general formula (II)

[0012]

Embedded image

A saccharide compound substituted with an azidohalogenobenzyl group (hereinafter, referred to as azidohalogenobenzyl group (II)) represented by the formula (wherein each symbol is as defined above).

(6) A monosaccharide, oligosaccharide or polysaccharide is obtained by reacting with an azidohalogenobenzyl derivative (I) (5)
The saccharide compound according to any one of the preceding claims.

(7) Azidohalogenobenzyl derivative (I)
Is reacted with a hydroxyl group-containing compound to convert the hydrogen atom of the hydroxyl group of the hydroxyl group-containing compound into an azidohalogenobenzyl group (I
A method for protecting a hydroxyl group, which comprises substituting I).

(8) The protection method according to (7), wherein the hydroxyl group-containing compound is a compound having a sugar structure.

(9) Azidohalogenobenzyl derivative (I)
A reagent for protecting a hydroxyl group.

(10) The reagent according to (9), wherein in the general formula (I), X represents a halogen atom or an imidoyloxy group.

(11) The reagent according to (9), wherein in formula (I), B represents a hydrogen atom and X represents a halogen atom.

(12) Azidohalogenobenzyl derivative (I)
Is 4-azido-3-chlorobenzylbromide
(9) The reagent according to the above.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the definition of each substituent is as follows. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a chlorine atom and a bromine atom are preferred. More preferably, it is a chlorine atom. The group capable of reacting with the hydroxyl group is a group capable of reacting with the hydroxyl group and leaving together with the hydrogen atom of the hydroxyl group, and includes, for example, the above-described halogen atom and imidoyloxy group. Preferably it is a halogen atom. Here, the imidoyloxy group is an imidoyloxy group having an alkyl group having 1 to 5 carbon atoms or the like, and may further have a halogen atom or the like as a substituent. Specifically,
Examples thereof include a 1,1-trichloroethaneimidoyloxy group.

The azidohalogenobenzyl derivative (I) of the present invention preferably includes 4-azido-3-chlorobenzyl bromide.

The azidohalogenobenzyl derivative (I) of the present invention can be synthesized as follows when X is a halogen atom, for example.

[0024]

Embedded image

(Wherein X ¹ represents a halogen atom, and A and B have the same meanings as described above). That is, aminohalogenotoluene represented by the general formula (III) [hereinafter referred to as aminohalogenotoluene (III)] Is treated with sodium nitrite in an aqueous hydrochloric acid solution and then with sodium azide to give a compound of the general formula (I)
Azidohalogenotoluene [hereinafter referred to as azidohalogenotoluene (IV)] represented by V) [New Experimental Chemistry Course XVI: Synthesis and Reaction of Organic Compounds III, Maruzen, 1665]
-1666 (1978)]. Then, for example,
By reacting with N-halogenosuccinimide in the presence of a catalyst such as 2'-azobisisobutyronitrile (AIBN) in an appropriate solvent, if necessary, in a stream of an inert gas, and protected from light, the present invention Of the azidohalogenobenzyl derivative (I) [New Experimental Chemistry Course XVI.
Synthesis and Reaction of Organic Compounds I, Maruzen, pp. 336-339 (197)
9)]. Instead of N-halogenosuccinimide, halogen gas such as chlorine gas or bromine gas, or solid or liquid halogen such as solid iodine or liquid bromine may be used.

The synthesis of azidohalogenotoluene (IV) is usually carried out by adding 1 to 10 equivalents, preferably 1 to 5 equivalents, more preferably 1 to 2 equivalents of sodium nitrite to aminohalogenotoluene (III), After stirring at −10 ° C. to room temperature for several minutes to several tens minutes, 1 to 5 equivalents, preferably 1 to 2 equivalents of sodium azide is added to aminohalogenotoluene (III), and further −10 ° C. to room temperature For several minutes to several tens minutes.

Examples of the starting material, aminohalogenotoluene (III), include, for example, 2-amino-4-fluorotoluene, 2-amino-5-fluorotoluene, 2-amino-6-fluorotoluene, 3-amino-4- Fluorotoluene, 3-amino-5-fluorotoluene, 3-
Amino-6-fluorotoluene, 4-amino-2-fluorotoluene, 4-amino-3-fluorotoluene, 2
-Amino-3-chlorotoluene, 2-amino-5-chlorotoluene, 2-amino-6-chlorotoluene, 3-amino-4-chlorotoluene, 3-amino-6-chlorotoluene, 4-amino-2- Chlorotoluene, 4-amino-3-chlorotoluene, 2-amino-5-bromotoluene, 2-amino-6-bromotoluene, 2-amino-5
-Iodotoluene, 4-amino-2-iodotoluene,
4-amino-2,6-dichlorotoluene, 2-amino-
4,6-dichlorotoluene, 4-amino-2,5-dichlorotoluene and the like can be mentioned.

In the reaction of azidohalogenotoluene (IV) with N-halogenosuccinimide, usually, 1 to 5 equivalents, preferably 1 to 2 equivalents, of N-halogenosuccinimide relative to azidohalogenotoluene (IV) are used. . Examples of the solvent used in the reaction include aromatic hydrocarbons such as benzene, toluene, and xylene, and halogenated hydrocarbons such as dichloromethane and dichloroethane. However, it is preferable to use these solvents in an anhydrous state. The reaction temperature is usually the boiling point of the solvent used, and the reaction time is usually tens of minutes to tens of hours.

Examples of the N-halogenosuccinimide used include N-chlorosuccinimide, N-bromosuccinimide, N-iodosuccinimide and the like.

When X is an imidoyloxy group, for example, a method of reacting the corresponding azidohalogenobenzyl alcohol with trichloroacetonitrile in the presence of sodium hydride in a solvent such as dichloromethane [Exp. Chemistry Course Organic Synthesis VIII, Maruzen, 274-275
(1990)] or the corresponding azidohalogenobenzyl alcohol is reacted with trichloroacetonitrile in the presence of cesium carbonate in a solvent such as dichloromethane to obtain the azidohalogenobenzyl derivative (I) by a method known per se. be able to.

The obtained azidohalogenobenzyl derivative (I) of the present invention is useful for protecting a hydroxyl group of a hydroxyl group-containing compound. The hydroxyl group-containing compound includes a compound having a sugar structure. By reacting the compound having a saccharide structure with the azidohalogenobenzyl derivative (I) of the present invention, a saccharide compound in which the hydrogen atom of the hydroxyl group of the compound is substituted with the azidohalogenobenzyl group (II) is obtained.

Examples of the compound having a sugar structure include monosaccharides (glucose, arabinose, fucose, galactose, mannose, xylose, fructose,
Lyxose, allose, alinose, ribose, talose, gulose, idose, altrose, sorbitol, mannitol, glucosamine, etc., oligosaccharides (maltose, isomaltose, turanose, gentiobiose, melibiose, planteobiose, primererose, bicianose, nigerose, lamina) Liviose,
Rutinose, cellobiose, xylobiose, maltotriose, gentianose, meletitose, planteose, ketose, trehalose, sucrose, lactose, raffinose, xyliotriose, etc.), polysaccharides (amylose, ficoll, dextrin, starch, dextran, polydextros, pullulan) , Cyclodextrin, glucomannoglycan, glucomannan, guar gum, gum arabic, glycosaminoglycan, etc., and complex carbohydrates (glycopeptides, glycoproteins, glycolipids, proteoglycans, etc.). Further, a part of the hydroxyl group of the compound containing these sugar structures is, for example, an acetyl group,
Acetyl groups such as acetylethylcarbonyl group and benzoyl group, for example, those protected with substituted alkyl groups such as benzyl group, nitrobenzyl group, azidobenzyl group and methoxybenzyl group are also included in the compound having a sugar structure according to the present invention. included. Furthermore, compounds containing these sugar structures include:
Also included are compounds containing a sugar structure that is bonded to, for example, a resin or polymer via a linker.

A saccharide compound in which at least one hydrogen atom of a hydroxyl group is substituted by an azidohalogenobenzyl group (II) can be obtained by reacting a compound having the above saccharide structure with an azidohalogenobenzyl derivative (I). .
The reaction is usually carried out using N, N-dimethylformamide (DM
It is carried out by stirring at 0 ° C. to room temperature in a solvent such as F) for several tens minutes to several hours. At this time, it is preferable to use, for example, sodium hydride or the like in order to activate the hydroxyl group.

Examples of the sugar compound having at least one hydrogen atom of a hydroxyl group substituted by an azidohalogenobenzyl group (II) include, for example, methyl 6-O- (4-azido-3).
-Chlorobenzyl) -2,3,4-tri-O-benzyl-D-glucopyranoside, methyl 4-O- (4-azido-3-chlorobenzyl) -2,3,6-tri-O-benzyl-D -Glucopyranoside and the like.

The method for protecting a hydroxyl group according to the present invention comprises reacting an azidohalogenobenzyl derivative (I) with a hydroxyl group-containing compound to replace a hydrogen atom of the hydroxyl group of the hydroxyl group-containing compound with an azidohalogenobenzyl group (II). It is performed by The hydroxyl group-containing compound used in the present invention, for example compounds containing a saccharide structure described above, or an oxygen atom of the ring forming the sugar structure of a compound containing the sugar structure is replaced by a sulfur atom or CH ₂ Although the compounds are preferably exemplified, the hydroxyl group-containing compound is not limited to the above compounds, and may be any compound having a hydroxyl group.

The reaction between the azidohalogenobenzyl derivative (I) and the compound containing a hydroxyl group may be performed according to the reaction between the azidohalogenobenzyl derivative (I) and the compound having a sugar structure.

By the hydroxyl protecting group thus obtained,
That is, a compound protected by an azidohalogenobenzyl group (II) is described, for example, in Y. Oikawa et al., Tetrahedron
Deprotection can be easily performed under mild conditions by the method described in Letters, 23, page 885 (1982). That is, 1 to 5 equivalents triphenylphosphine (PPh ₃₎ relative azidohalogenobenzyl group (II), preferably added and stirred 1 to 2 equivalents, further water, acetic acid and 2,3-dichloro-5,6 -Dicyanobenzoquinone (D
DQ) with respect to the azidohalogenobenzyl group (II)
The protective group can be easily removed by adding to 5 equivalents, preferably 1 to 2 equivalents, and stirring. Further, silica gel may be used instead of acetic acid.

[0038]

EXAMPLES The present invention will be described in more detail with reference to production examples, experimental examples and examples, but the present invention is not limited to these examples.

Production Example 1: Synthesis of 4-azido-3-chlorotoluene 4-amino-3-chlorotoluene (14.16 g, 0.1 mol)
Was dissolved in a mixture of concentrated hydrochloric acid (50 ml), water (400 ml) and DMF (100 ml), and cooled with ice-brine. To this, an aqueous solution (50 ml) of sodium nitrite (6.9 g, 0.1 mol) was added at -5 ° C.
It was added dropwise at ５5 ° C. over 20 minutes. After further stirring for 10 minutes, an aqueous solution of sodium azide (6.5 g, 0.1 mol) (50 m
l) was added dropwise at 10 ° C to 20 ° C over 20 minutes. The reaction solution was further stirred for 1.5 hours and extracted with diethyl ether.
(150 ml × 3). The ether layers were combined, washed with saturated aqueous sodium hydrogen carbonate and saturated saline, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to give 17.14 g of the title compound as a brown oil. MS (EI): M ⁺ = 167, 169 ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.19 (d, 1 H), 7.06 (m, 2 H),
2.31 (s, 3H)

Example 1 Synthesis of 4-azido-3-chlorobenzylbromide 4-Azido-3-chlorotoluene (17.14 g, 0.1 mol) was dissolved in anhydrous benzene (80 ml), and N-bromosuccinimide (19.6 g, 0.11 mol) and AIBN (1.64 g, 0.01 mo
l) was added, and the mixture was refluxed for 10 hours in a nitrogen stream under light shielding. water
(100 ml) and filtered. The aqueous layer of the filtrate was taken and extracted with ether. The organic layers were combined, washed with brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the obtained brown oil was purified by silica gel column chromatography (eluent: hexane) to give the title compound (14.2 g, yield 58%). Melting point: 75-77 ° C ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.42 (d, 1H), 7.31 (dd, 1H),
7.14 (d, 1H), 4,42 (s, 2H)

Example 2 Synthesis of Methyl 6-O- (4-azido-3-chlorobenzyl) -2,3,4-tri-O-benzyl-D-glucopyranoside Methyl 2,3,4-tri-O -Benzyl-D-glucopyranoside (1.16 g, 2.5 mmol) was dissolved in DMF (10 ml) and sodium hydride (60% in oil, 120 mg, 3.00 m
mol) and stirred for 15 minutes. Subsequently, 4-azido-3
-Chlorobenzyl bromide (740 mg, 3.00 mmol) was added in small portions. After stirring at 0 ° C. for 30 minutes and at room temperature for 3 hours, ice water was added to the reaction solution, and the mixture was extracted with ethyl acetate. The solvent was removed under reduced pressure, and the resulting residue was subjected to silica gel column chromatography (eluent; hexane: ethyl acetate = 4:
Purification in 1) gave the title compound as a yellow oil (1.48 g, 94% yield). ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.37-7.03 (m, 18H), 5.00-
4.35 (m, 9H), 3.98 (t, 1H), 3.76-3.52 (m, 5H), 3.38 (s, 3
H)

Example 3: Synthesis of methyl 4-O- (4-azido-3-chlorobenzyl) -2,3,6-tri-O-benzyl-D-glucopyranoside The title compound was obtained as a yellow oil in the same manner as in Example 2 using 3,6-tri-O-benzyl-D-glucopyranoside (565 mg, yield 90%). ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.36-7.24 (m, 15H), 7.07
(d, 1H), 6.97 (m, 2H), 4.98 (d, 1H), 4.80-4.62 (m, 6H),
4.43 (d, 1H), 4.34 (d, 1H), 3.94 (t, 1H), 3.72-3.52 (m, 5
H), 3.38 (s, 3H)

Experimental Example 1 Elimination of a protecting group (methyl 2,
Synthesis of 3,4-tri-O-benzyl-D-glucopyranoside) Methyl 6-O- (4-azido-3-chlorobenzyl)
-2,3,4-tri-O-benzyl-D-glucopyranoside (126 mg, 0.2 mmol) was added to tetrahydrofuran (TH
F, 1 ml), PPh ₃ (63 mg, 0.24 mmol) was added, and the mixture was stirred at room temperature for 1 hour. Then add water (1
0 μl), glacial acetic acid (10 ml) and DDQ (68 mg, 0.3 mmol)
Was added and the mixture was further stirred for 1.5 hours. The reaction solution was diluted with ethyl acetate, and a 5% aqueous ascorbic acid solution, a saturated aqueous sodium hydrogen carbonate solution,
Washed with saturated saline. After drying over anhydrous sodium sulfate,
The solvent was removed under reduced pressure to give a brown oil. Purification by silica gel column chromatography (eluent; dichloromethane: ethyl acetate = 40: 1) gave the title compound as a colorless oil (86 mg, yield 92%). ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.37-7.24 (m, 15H), 4.99
(d, 1H), 4.90-4.77 (m, 3H), 4.65 (dd, 2H), 4.58 (d, 1H),
4.00 (t, 1H), 3.76-3.62 (m, 3H), 3.55-3.47 (m, 2H), 3.36
(s, 3H), 1.63 (t, 1H) Similar results were obtained by adding silica gel instead of acetic acid.

Experimental Example 2: Acid resistance test Methyl 6-O- (4-azido-3-chlorobenzyl)
-2,3,4-Tri-O-benzyl-D-glucopyranoside (the compound of Example 2) was exposed to 2 equivalents of boron trifluoride-diethyl ether in methylene chloride at room temperature but was not decomposed. . [2- (4-methoxybenzyloxy) ethyl] benzene having a 4-methoxybenzyl group as a protecting group for a hydroxyl group, and methyl 6-O- (4-
Azidobenzyl) -2,3,4-tri-O-benzyl-
A similar experiment was performed using D-glucopyranoside. As a result, [2- (4-methoxybenzyloxy) ethyl] benzene is rapidly decomposed and methyl 6-O- (4
-Azidobenzyl) -2,3,4-tri-O-benzyl-D-glucopyranoside was degraded by about 25% in 6 hours.
From the above, it can be seen that, unlike the conventional hydroxyl-protecting group, the azidohalogenobenzyl group according to the present invention shows excellent stability to acids.

Experimental Example 3: Selective elimination test (1) Synthesis of ethylene glycol protected with azidochlorobenzyl group and methoxybenzyl group: 1-azido-
Synthesis of 2-chloro-4- (4-methoxybenzyloxyethoxymethyl) benzene 2- (4-methoxybenzyloxy) ethanol (500 m
g, 2.75 mmol) in DMF (10 ml), and sodium hydride (132 mg, 3.30 mmol in 60% oil) was added at 0 ° C.
Stirred for minutes. Subsequently, 4-azido-3-chlorobenzyl bromide (813 mg, 3.30 mmol) was added in small portions.
After the reaction solution was stirred at 0 ° C. for 30 minutes and at room temperature for 2 hours, ice water was added and extracted with ether. The ether layer was washed with water and then with a saturated saline solution, and dried over anhydrous sodium sulfate.
The solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography (eluent; hexane: ethyl acetate = 10: 1) to give the title compound as a yellow oil (805 mg, yield Rate 84%). ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.39 (d, 1 H), 7.30-7.24 (m,
3H), 7.13 (d, 1H), 6.90-6.85 (m, 2H), 4.51 (s, 4H), 3.80
(s, 3H), 3.64 (s, 4H)

(2) Elimination of azidochlorobenzyl group: 2
Synthesis of-(4-methoxybenzyloxy) ethanol 1-azido-2-chloro-4- obtained in the above (1)
(4-Methoxybenzyloxyethoxymethyl) benzene (174 mg, 0.5 mmol) was dissolved in THF (1 ml), and PPh was dissolved.
₃ (157 mg, 0.6 mmol) was added, and the mixture was stirred at room temperature for 1 hour. Subsequently, water (10 ml), glacial acetic acid (10 ml) and DDQ (159 mg, 0.7 mmol) were added to the reaction solution, and the mixture was further stirred at room temperature for 1 hour. The reaction solution was diluted with ethyl acetate, and washed with a 5% aqueous ascorbic acid solution, a saturated aqueous sodium bicarbonate solution, and a saturated saline solution.
After drying over anhydrous sodium sulfate, the solvent was removed under reduced pressure,
The resulting brown oil was purified by silica gel column chromatography (eluent; dichloromethane: ethyl acetate = 2:
Purification in 1) gave the title compound as a yellow oil (68 mg, 75% yield). ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.27 (m, 2H), 6.89 (m, 2H),
4.49 (s, 2H), 3.81 (s, 3H), 3.74 (m, 2H), 3.57 (m, 2H)

(3) Elimination of methoxybenzyl group: 2-
Synthesis of (4-azido-3-chlorobenzyloxy) ethanol 1-azido-2-chloro-4- obtained in above (1)
(4-Methoxybenzyloxyethoxymethyl) benzene (348 mg, 1 mmol) was dissolved in THF (2 ml), and water (0.1 m
l) and DDQ (34 mg, 1.50 mmol) were added, and the mixture was stirred at room temperature for 7 hours. The reaction solution was diluted with ethyl acetate, washed with a 5% aqueous ascorbic acid solution, a saturated aqueous sodium bicarbonate solution, and a saturated saline solution, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the resulting brown oil was purified by silica gel column chromatography (eluent; hexane: ethyl acetate = 2: 1) to give the title compound as a yellow oil (2
01 mg, yield 88%). ¹ H-NMR (270 MHz, CDCl ₃ ) δ: 7.38 (d, 1H), 7.26 (m, 1H),
7.15 (d, 1H), 4.51 (s, 2H), 3.78 (t, 2H), 3.60 (t, 2H)

As described above, the azidohalogenobenzyl group according to the present invention can be deprotected under conditions different from the conventional methoxybenzyl group. That is, the azidohalogenobenzyl group is not deprotected by DDQ and water alone, but the methoxybenzyl group is deprotected, while the azidohalogenobenzyl group is deprotected by PPh ₃ , DDQ, water and acetic acid,
The methoxybenzyl group is not deprotected. Thus, the use of the azidohalogenobenzyl groups according to the invention together with conventional protecting groups allows for the selective elimination of the protecting groups.

The following Examples 4 to 9 are examples of the synthesis of sugar chains by the solid phase synthesis method using the protecting group of the present invention. In addition, the meaning of the abbreviation in a reaction formula is as follows. Bzl: benzyl Ph: phenyl Trt: triphenylmethyl MPM: 4-methoxybenzyl Bz: benzoyl Tce: 2,2,2-trichloroethyl Troc: 2,2,2-trichloroethyloxycarbonyl Et: ethyl Bu: butyl Tf: Trifluoromethylsulfonyl Ac: acetyl

Example 4: Synthesis of phenyl 6-O- (4-azido-3-chlorobenzyl) -2,3,4-tri-O-benzyl-1-thio-D-glucopyranoside (4)

[0051]

Embedded image

(A) 1,6-anhydro-2,3,4-
Tri-O-benzyl-β-D-glucopyranoside (2)
Sodium hydride (13.2 g, 0.33 mol in 60% oil) was washed with anhydrous ether and suspended in DMF (100 ml). 1,6-Anhydro-β-D-glucopyranoside (1) (16.2 g, 0.1 mol) was added thereto, and the mixture was stirred at room temperature for 30 minutes. It was then cooled to 0 ° C. and benzyl bromide (39.3 ml, 0.1%
33 mol) was added dropwise, and the mixture was stirred at room temperature for 2 hours. water
(200 ml), and extracted three times with ethyl acetate. The organic layers were combined, washed with saturated saline, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to obtain white crystals. Recrystallized from hot methanol to give white crystals of 1,6-anhydro-
2,3,4-Tri-O-benzyl-β-D-glucopyranoside (2) was obtained (38.2 g, yield 88%).

(B) phenyl 2,3,4-tri-O-
Synthesis of benzyl-1-thio-D-glucopyranoside (3) 1,6-anhydro-2,3,4-tri-O-benzyl-β-D-glucopyranoside (2) (15.0 g, 34.7 mmol)
l) and phenylthiotrimethylsilane (19.7 ml, 104 mmo
l) in dichloromethane solution (100 ml) was added to zinc iodide (11.1
g, 34.7 mmol) and stirred at room temperature for 4 hours. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. Residue in methanol
(100 ml), add 1N hydrochloric acid (50 ml), and add
Stirred for minutes. After removing methanol under reduced pressure, the mixture was extracted with ethyl acetate, and the organic layer was washed with a saturated aqueous sodium hydrogen carbonate solution and then with a saturated saline solution. After drying over anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the resulting oil was crystallized in hexane to give phenyl 2,3,4-
Tri-O-benzyl-1-thio-D-glucopyranoside (3) was obtained (19.5 g, yield 89%).

(C) phenyl 6-O- (4-azido-
Synthesis of 3-chlorobenzyl) -2,3,4-tri-O-benzyl-1-thio-D-glucopyranoside (4) Phenyl 2,3,4-tri-O-benzyl-1-thio-D-glucopyranoside (3) To a solution of (1.09 g, 2.00 mmol) in DMF (10 ml) was added sodium hydride (96% oil, 96 m
g, 2.40 mmol) and stirred at room temperature for 15 minutes. Cool to 0 ° C. and add 4-azido-3-chlorobenzyl bromide (592
mg, 2.40 mmol) and stirred at room temperature for 4 hours. Water (30 ml) was added, and the mixture was extracted twice with ethyl acetate. The organic layers were combined, washed with brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography (eluent; hexane: ethyl acetate = 5: 1) to give pale yellow crystals of phenyl 6-O- (4-azido-3- Chlorobenzyl)-
2,3,4-Tri-O-benzyl-1-thio-D-glucopyranoside (4) was obtained (1.33 g, 94% yield).

Example 5: Phenyl 6-O- (4-azido-3-chlorobenzyl) -2,3,4-tri-O-benzoyl-1-thio-β-D-glucopyranoside (1
Synthesis of 1)

[0056]

Embedded image

[0057]

Embedded image

(A) Synthesis of phenyl 6-O-triphenylmethyl-1-thio-β-D-glucopyranoside (6) Phenyl 1-thio-β-D-glucopyranoside (5)
(7.01 g, 25.8 mmol), triphenylmethyl chloride (9.
33 g, 33.5 mmol) were suspended in pyridine (20 ml) and refluxed for 5 hours. After removing the solvent under reduced pressure, the residue was dissolved in ethyl acetate, washed with water and then with saturated saline, and dried over anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure was purified by silica gel column chromatography (eluent; dichloromethane: ethyl acetate = 1: 1),
Phenyl 6-O-triphenylmethyl-1 as a white solid
-Thio-β-D-glucopyranoside (6) was obtained (13.1).
g, yield 99%).

(B) phenyl 2,3,4-tri-O-
Synthesis of (4-methoxybenzyl) -6-O-triphenylmethyl-1-thio-β-D-glucopyranoside (7) Phenyl 6-O-triphenylmethyl-1-thio-β
To a solution of -D-glucopyranoside (6) (13.0 g, 25.3 mmol) in DMF (80 ml) was added sodium hydride (3.22% in 60% oil).
g, 80.5 mmol) and stirred at room temperature for 20 minutes. After cooling to 0 ° C, 4-methoxybenzyl chloride (12.6 g, 80.5 g
mmol) and the mixture was stirred at room temperature overnight. Add cold water, extract twice with ether, combine the combined ether layers with water,
Then, it was washed with saturated saline. After drying over anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (eluent; hexane: ethyl acetate = 3: 1) to give phenyl 2,2 as a white oil.
3,4-tri-O- (4-methoxybenzyl) -6-O
-Triphenylmethyl-1-thio-β-D-glucopyranoside (7) was obtained (18.8 g, yield 85%).

(C) phenyl 2,3,4-tri-O-
Synthesis of (4-methoxybenzyl) -1-thio-β-D-glucopyranoside (8) phenyl 2,3,4-tri-O- (4-methoxybenzyl) -6-O-triphenylmethyl-1-thio -Β-
Formic acid (8 ml) was added to a solution of D-glucopyranoside (7) (3.44 g, 3.93 mmol) in ether (8 ml), and the mixture was stirred at room temperature for 5 hours. The reaction solution was washed with water, a saturated aqueous solution of sodium hydrogencarbonate, and a saturated aqueous solution of sodium chloride in that order, and then the solvent was removed under reduced pressure. The residue was suspended in a mixture of ethanol (5 ml) and a 1N aqueous sodium hydroxide solution (5 ml) and stirred at room temperature overnight.
After distilling off ethanol under reduced pressure, the mixture was extracted twice with ether. After washing the combined ether layers with saturated saline,
Dry over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (eluent: hexane: ethyl acetate = 2: 1 → 1: 1) to give phenyl 2,3,4-tri-O- ( 4
-Methoxybenzyl) -1-thio-β-D-glucopyranoside (8) was obtained (1.28 g, yield 51%).

(D) Phenyl 6-O- (4-azido-
3-chlorobenzyl) -2,3,4-tri-O- (4-
Synthesis of methoxybenzyl) -1-thio-β-D-glucopyranoside (9) phenyl 2,3,4-tri-O- (4-methoxybenzyl) -1-thio-β-D-glucopyranoside (8)
(1.25 g, 1.98 mmol) and 4-azido-3-chlorobenzyl bromide (584 mg, 2.37 mmol) in DMF (10 ml) were added with sodium hydride (95 mg, 2.37 mmol in 60% oil). And stirred at room temperature for 3 hours. Cold water was added, and the mixture was extracted twice with ether. The combined ether layers were washed with water and then with saturated saline, and then dried over anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure is subjected to silica gel column chromatography (eluent; hexane: ethyl acetate =
4: 1) to give phenyl 6-O- (4
-Azido-3-chlorobenzyl) -2,3,4-tri-
O- (4-Methoxybenzyl) -1-thio-β-D-glucopyranoside (9) was obtained (1.25 g, yield 79%).

(E) phenyl 6-O- (4-azido-
Synthesis of 3-chlorobenzyl) -1-thio-β-D-glucopyranoside (10) phenyl 6-O- (4-azido-3-chlorobenzyl) -2,3,4-tri-O- (4-methoxy (Benzyl) -1-thio-β-D-glucopyranoside (9) (1.2
4 g, 1.55 mmol) in dichloromethane (10 ml).
(0.5 ml) and DDQ (1.41 g, 6.21 mmol) were added, and the mixture was stirred at room temperature for 3 hours. A 5% L-ascorbic acid aqueous solution was added, and the mixture was stirred for a while, and then extracted with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium hydrogen carbonate and then with a saturated saline solution, and then dried over anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure was purified by silica gel column chromatography (eluent; dichloromethane: ethyl acetate = 1: 3), and phenyl 6-O- as yellow crystals was obtained.
(4-azido-3-chlorobenzyl) -1-thio-β-
D-glucopyranoside (10) was obtained (584 mg, yield 86)
%).

(F) Phenyl 6-O- (4-azido-
Synthesis of 3-chlorobenzyl) -2,3,4-tri-O-benzoyl-1-thio-β-D-glucopyranoside (11) phenyl 6-O- (4-azido-3-chlorobenzyl) -1- Thio-β-D-glucopyranoside (10) (5
80 mg, 1.32 mmol) in pyridine (5 ml) at 0 ° C.
Benzoyl chloride (609 μl, 5.28 mmol) was added, and the mixture was stirred at room temperature for 2 hours. Water was added, the mixture was extracted with ethyl acetate, and the organic layer was washed with saturated saline and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to give phenyl 6-O- (4-azido-3-chlorobenzyl) -2,3,4-tri-O-benzoyl-1-thio- as pale yellow crystals.
β-D-glucopyranoside (11) was obtained (934 mg, yield
94%).

Example 6: Synthesis of a polystyrene resin derivative of the formula (17) having 2,3,4-tri-O-benzyl-glucopyranoside immobilized thereon

[0065]

Embedded image

[0066]

Embedded image

(A) 4-bromomethylphenylacetic acid
Synthesis of 2,2,2-trichloroethyl ester (13) 4-bromomethylphenylacetic acid (12) (10.3 g, 44.8
mmol) was suspended in dichloromethane (30 ml), trifluoroacetic anhydride (9.28 ml, 67.2 mmol) was added at 0 ° C., and the mixture was stirred for 30 minutes. Next, 2,2,2-trichloroethanol (6.47 ml, 67.2 mmol) was added dropwise, and the mixture was stirred at room temperature overnight. After washing with water, a saturated aqueous solution of sodium hydrogencarbonate and saturated saline, the solution was dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain a colorless oil. This oily substance was allowed to stand overnight, whereby white crystals of 4-bromomethylphenylacetic acid 2,2,2-trichloroethyl ester (1
3) was obtained (15.9 g, yield 98%).

(B) Synthesis of 4- (4-hydroxymethylphenylacetoxymethyl) phenylacetic acid 2,2,2-trichloroethyl ester (14) A solution of cesium carbonate (1.63 g, 5.00 mmol) in water (50 ml) was prepared. , 4-bromomethylphenylacetic acid (12) (1.15 g,
(5.00 mmol) and refluxed for 1 hour. After cooling, the mixture was concentrated to dryness under reduced pressure, and the obtained residue was suspended in DMF (10 ml). Here, 4-bromomethylphenylacetic acid
2,2,2-trichloroethyl ester (13) (1.80
g, 5.00 mmol) and stirred at room temperature overnight. Add water,
The mixture was extracted with ethyl acetate, and the organic layer was washed with saturated saline.
After drying over anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the resulting oil was purified by silica gel column chromatography (eluent; dichloromethane: ethyl acetate = 15: 1) to give 4- (4-hydroxyl) as a white solid. Methylphenylacetoxymethyl) phenylacetic acid 2,2,2-trichloroethyl ester (14) was obtained (994 mg, yield: 45%).

(C) Synthesis of 2,2,2-trichloroethyl ester derivative of formula (15) 4- (4-hydroxymethylphenylacetoxymethyl) phenylacetic acid 2,2,2-trichloroethyl ester (14) (1.94 g, 4.35 mmol), phenyl 2,3
4-tri-O-benzyl-6-O- (2,2,2-trichloroethyloxycarbonyl) -1-thio-D-glucopyranoside (2.94 g, 3.95 mmol), iodosobenzene
(956 mg, 4.35 mmol), silver perchlorate (328 mg, 1.58 mmo
l), Molecular sieve (registered trademark) 4A (about 1 g)
Was suspended in ether (15 ml) and the mixture was stirred at room temperature under a nitrogen atmosphere.
Stir for 30 minutes. After cooling to 0 ° C., trimethylsilyl chloride (101 μl, 0.79 mmol) was added and the mixture was stirred for 30 minutes. The reaction solution was filtered and the filtrate was saturated aqueous sodium hydrogen carbonate,
Then, after washing with saturated saline, it was dried over anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure was purified by silica gel column chromatography (eluent; hexane: ethyl acetate = 4: 1) to give 2,2,2 of the formula (15).
-The trichloroethyl ester derivative was obtained as a colorless oil (3.22 g, yield 77%). α-anomer / β-anomer =
95/5

(D) Synthesis of the carboxylic acid derivative of the formula (16) The 2,2,2-trichloroethyl ester derivative (3.22 g, 3.06 mmol) of the formula (15) was dissolved in 90% acetic acid, and powdered zinc (4.00 g, 61.1 mmol) and stirred at room temperature for 2 hours. The reaction solution was filtered, the filtrate was diluted with ethyl acetate, washed with saturated saline, and dried over anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure was purified by silica gel column chromatography (eluent; dichloromethane: methanol = 97: 3) to give the carboxylic acid derivative of the formula (16) as a white solid (2.11 g, Yield 93%).

(E) Synthesis of polystyrene resin derivative of formula (17) Carboxylic acid derivative of formula (16) (896 mg, 1.20 mmol)
Aminomethylated polystyrene resin (0.83 mmol / g, 1.20
g, 1 mmol), diisopropylcarbodiimide (DI
C) (219 μl, 1.40 mmol), 1-hydroxybenzotriazole (HOBt) (189 mg, 1.40 mmol) and triethylamine (195 μl, 1.40 mmol) were added to dichloromethane (10
ml) and shaken at room temperature for 2 hours. The resin was collected by filtration, washed with DMF and dichloromethane, and dried under reduced pressure to obtain a polystyrene resin derivative of the formula (17).
(1.88 g, about 100% yield).

Example 7: Polystyrene resin derivative of the formula (17) and 4-azido-3- of the formula (4) or (11)
Glycosylation reaction with chlorobenzylated thioglycosides

[0073]

Embedded image

Formula (4) obtained in Example 4 or Example 5
(R = benzyl) or thioglycoside (75 mmol) of the formula (11) (R = benzoyl), the compound of the formula (1) obtained in Example 6
7) Polystyrene resin derivative (25 mmol), tetrabutylammonium salt (25 mmol) (When R = benzyl, use tetrabutylammonium perchlorate; when R = benzoyl, use tetrabutylammonium trifluoromethanesulfonate) ) And Molecular Sieve® 4A were suspended in dichloromethane (1 ml) and shaken for 15 minutes. Here, N-bromosuccinimide (15 mg,
83 mmol) and shaken overnight at room temperature. The molecular sieve (registered trademark) 4A was removed, and the resin was collected by filtration, washed with dichloromethane, dried under reduced pressure, and treated with the formula (1)
8) A polystyrene resin derivative was obtained. 4-azido-3
The rate of introduction of the chlorobenzylated glycoside into the resin is 30;
７５75%. If the introduction rate is low,
It should be repeated times.

Example 8: Removal of 4-azido-3-chlorobenzyl group from polystyrene resin derivative of formula (18)

[0076]

Embedded image

Polystyrene resin derivative of formula (18) containing a hydroxyl group protected by a 4-azido-3-chlorobenzyl group (about 70 mg, 10 to 15 μmol of 4-azido-3-chlorobenzyl group is present) And PPh ₃ (20 mg, 75μ
mol) was added to THF (1 ml) and shaken at room temperature for 1.5 hours. The resin was collected by filtration, washed with THF, and added again to THF (1 ml). Here, DDQ (8.5 mg, 37.
5 μmol) and 50% acetic acid aqueous solution (20 μl), and add
Shake for hours. After filtering the resin, the resin was washed with DMF and then with dichloromethane, and dried under reduced pressure to quantitatively obtain a polystyrene resin derivative of the formula (19).

Example 9: Polystyrene resin derivative of the formula (19) and 4-azido-3- of the formula (4) or (11)
Glycosylation reaction with chlorobenzylated thioglycosides

[0079]

Embedded image

Formula (4) (R = benzyl) or Formula (11)
(R = benzoyl) thioglycoside (75 mmol), polystyrene resin derivative of formula (19) (8 mmol), tetrabutylammonium salt (25 mmol) (when R = benzyl, tetrabutylammonium perchlorate is used. When R = benzoyl, tetrabutylammonium trifluoromethanesulfonate) and Molecular Sieve 4A were suspended in dichloromethane (1 ml) and shaken for 15 minutes. Here, N-bromosuccinimide (15 m
g, 83 mmol) and shaken overnight at room temperature. Molecular sieve (registered trademark) 4A was removed, the resin was collected by filtration, washed with dichloromethane, and then dried under reduced pressure to obtain a polystyrene resin derivative of the formula (20). The introduction ratio of 4-azido-3-chlorobenzylated glycoside to the resin was 33%.

[0081]

As described above, by disposing an azide group on a benzyl group, it is possible to easily remove the protecting group under mild conditions by reducing and converting to an amino group when necessary. The acid resistance is improved by the halogeno group disposed on the benzyl group. Therefore, the azidohalogenobenzyl group according to the present invention is useful as a stable hydroxyl-protecting group even in solid-phase synthesis where the sugar chain is continuously placed under an acidic environment for elongation. Further, according to the present invention, it is possible to provide an azidohalogenobenzyl derivative into which such an azidohalogenobenzyl group can be introduced, a sugar compound protected using the derivative, and a method for protecting a hydroxyl group using the derivative.

Claims (12)

[Claims] 1. A compound of the general formula (I) (Wherein A represents a halogen atom, B represents a halogen atom or a hydrogen atom, and X represents a group capable of reacting with a hydroxyl group). 2. The azidohalogenobenzyl derivative according to claim 1, wherein in the general formula (I), X represents a halogen atom or an imidoyloxy group. 3. The azidohalogenobenzyl derivative according to claim 1, wherein in the general formula (I), B represents a hydrogen atom and X represents a halogen atom. 4. The azidohalogenobenzyl derivative according to claim 1, which is 4-azido-3-chlorobenzyl bromide. 5. The method according to claim 1, wherein at least one hydrogen atom of the hydroxyl group is
Formula (II) (Wherein, A represents a halogen atom and B represents a halogen atom or a hydrogen atom), a sugar compound substituted with an azidohalogenobenzyl group represented by the formula: 6. A monosaccharide, oligosaccharide or polysaccharide represented by the general formula (I): (Wherein A represents a halogen atom, B represents a halogen atom or a hydrogen atom, and X represents a group capable of reacting with a hydroxyl group), and is obtained by reacting with an azidohalogenobenzyl derivative represented by the following formula: Sugar compounds. 7. A compound of the general formula (I) (Wherein, A represents a halogen atom, B represents a halogen atom or a hydrogen atom, and X represents a group capable of reacting with a hydroxyl group). The hydrogen atom of the hydroxyl group of the hydroxyl group-containing compound is represented by the general formula (II): (Wherein, A represents a halogen atom and B represents a halogen atom or a hydrogen atom). A method for protecting a hydroxyl group, which comprises substituting an azidohalogenobenzyl group represented by the following formula: 8. The method according to claim 7, wherein the hydroxyl group-containing compound is a compound having a sugar structure. 9. A compound of the general formula (I) (Wherein A represents a halogen atom, B represents a halogen atom or a hydrogen atom, and X represents a group capable of reacting with a hydroxyl group), the reagent containing an azidohalogenobenzyl derivative represented by the formula: . 10. The reagent according to claim 9, wherein in the general formula (I), X represents a halogen atom or an imidoyloxy group. 11. The reagent according to claim 9, wherein in the general formula (I), B represents a hydrogen atom and X represents a halogen atom. 12. An azidohalogenobenzyl derivative represented by 4-
10. Azide-3-chlorobenzyl bromide.
The reagent as described.