BE821950A - Penicillins and cephalosporins as broad-spectrum antibiotics - having an alpha-(4-oxo pyrid-1-yl)alkanoamido side-chain - Google Patents

Abstract

Penicillins and cephalosporins of formula (I): (where R1-4 are H, halo, OH, alkyl, CF3, NO2, NH2, CN, -CO2H, -CO2Me, -CO2Et; or R1+R2 are -CH2CH2CH2CH2-or -CH:CH.CH:CH4 R5 is H, Me, -CO2H, -CO2Me, -CO2Et; R6 is a gp. X is H, OH, acetoxy, pyridinium, 5-methyl-1,3,4-thiadiazol-2-yl-thio or 1-methyl-1,2,3,-4-tetrazol-5-ylthio; R7 is H, alkanoyloxymethyl, alkanoylaminomethyl, alkoxycarbonylaminomethyl, &-alkanoyloxybenzyl (alkanoyl and alkoxy gps. have 1-5C); and R8 is H, -OMe), and their pharmaceutically acceptable salts are broad spectrum antibiotics for treatment of man and animals, as animal-feed additives and for disinfection of surfaces.

Description

       

  New derivatives of 4-oxo-pyridino-penicillins and cephalosporins useful in particular as antibacterials and their preparation process.

  
The present invention relates to novel derivatives

  
 <EMI ID = 1.1>

  
preparation process and pharmaceutical compositions containing these compounds as antibacterial agents.

  
These compounds possess high activity against a

  
large number of microorganisms. The cephalosporin derivatives according to the invention are particularly useful against penicillinase-producing microorganisms. The compounds of the invention are therapeutically effective as antibacterial agents in the treatment of infectious diseases caused by gram-positive and gram-negative bacteria.

  
in poultry and animals and in humans. In addition, the compounds

  
of the invention are useful as animal feed supplements and as active ingredients in germicidal preparations used as surface disinfectants.

  
The cleavage of penicillins to 6-amino penicillanic acid in 1959 and the cleavage of cephalosporin to give the corresponding 7-amino cephalosporanic acid made possible the synthesis of new synthetic penicillins and cephalosporins, which were not previously accessible by techniques. fermentation. Acylation of the amino group

  
led to derivatives containing a heterocyclic ring in the side chain at position 6, as in the case of the penicillin series, or in the side chain at the corresponding 7 position, as in the case of

  
the cephalosporin series. These heterocycles comprise the thiophene nucleus, as described for example in the patents of the United States of America.

  
n [deg.] 3,218,318, n [deg.] 3,449,338 and n [deg.] 3,498,979 (cephaloridine and cephalothin);

  
picoline, as described in the patent of the United States of America

  
 <EMI ID = 2.1>

  
of America n [deg.] 3,227,712; and various other nitrogenous heterocycles, including pyrrolidine and nicotinic acid, as disclosed in United States Patent No. [deg.] 3,308,120.

  
In each case, the heterocyclic residue is attached to a side chain, generally that of an acetyl radical, by one of the ring carbon atoms. The invention relates to oxo-4 pyridino derivatives which are directly linked to the acetyl radical through the heteroatom. Examples known to the Applicant containing this type of bond and constituting

  
In this view the closest prior art are the tetrazole nucleus in US Patent No. [deg.] 3,516,997 (cefazolin) and

V

  
certain quinazolinyl derivatives of penicillanic acid, in US Patent No. [deg.] 3,652,547.

  
A subject of the invention is therefore new derivatives of 4-oxo-pyridino-penicillins and cephalosporins, more particularly derivatives of 4-oxo-pyridino (substituted) acetamido-penicillins and-cephalosporins which can be represented by the general formula:

  

 <EMI ID = 3.1>


  
 <EMI ID = 4.1>

  
a hydrogen atom or a methyl, carboxy, carbomethoxy or carbethoxy group; R6 represents a group:

  

 <EMI ID = 5.1>


  
X represents a hydrogen atom or a hydroxy, acetoxy or pyridinium group,
(5-methyl-thiadiazol-1,3,4 yl-2) thio or (1-methyl-tetrazol-1,2,3,4 yl-5) thio; R7 represents a hydrogen atom or an alkanoyloxymethyl, alkanoylaminomethyl, alkoxycarbonylaminomethyl or p-alkanoyloxybenzyl group, in which the alkanoyl or alkoxy group contains 1 to 5 carbon atoms;

  
 <EMI ID = 6.1>

  
and their pharmaceutically acceptable salts.

  
The compounds of the invention are prepared by condensation of a 6-amino penicillanic or 7-amino cephalosporanic acid with a (substituted 4-oxo-pyridino) acetic acid as illustrated by the following reaction scheme:

  

 <EMI ID = 7.1>


  
All the compounds according to the invention contain an oxo-4 pyridino radical or a pyridone-4 ring in the terminal position of the acetamido side chain, as indicated in general formula (I) above. In the case of the penicillin series, the side chain

  
 <EMI ID = 8.1>

  
it is in position 7. The numbering system of these two series of compounds is illustrated below for the 6-amino penicillanic (IV) and 7-amino cephalosporanic (V) acids:

  

 <EMI ID = 9.1>


  
The pyridone-4 residue attached to the acetamido side chain

  
 <EMI ID = 10.1>

  
which positions 2, 3, 5 or 6 of the pyridine ring and include halogens and hydroxy, lower alkyl, trifluoromethyl, nitro, amino, cyano, carboxy, carbomethoxy and carbethoxy radicals. Halogens include fluoro, chloro, bromine and iodo radicals. The term lower alkyl denotes both straight chain and branched aliphatic hydrocarbon radicals.

  
 <EMI ID = 11.1>

  
isopropyl ,. butyl, isobutyl and tert-butyl.

  
In addition to the various substituents described above, the pyridone-4 residue can be considered as substituted with an attached saturated or unsaturated 6-membered ring. Thus, R. and R2, taken together with the carbon atoms to which they are attached, can be considered as

  
 <EMI ID = 12.1>

  
of the symmetry of the pyridine molecule, only one pair of neighboring symbols should be so defined. The invention is not directed to the dibenzopyridine or acridine tricyclic heterocyclic systems.

  
In addition to the obligatory substitution in position a of the acetamido portion of the molecule with an oxo-4 pyridino radical, the acetamido residue can also be substituted in a by a methyl or carboxy radical,

  
 <EMI ID = 13.1>

  
nique or 7-aminocephalosporanic. However, for uniformity of nomenclature, they will be referred to in the following as α-substituted acetamido derivatives. For example, in the case of an acid derivative

  
 <EMI ID = 14.1>

  
or carbomethoxy and carbethoxy also form part of the invention.

  
The invention essentially relates to the preparation and

  
description of α- (oxo-4 pyridino) -acetamido side chain derivatives

  
antibiotics of the β-lactam series. These derivatives are prepared

  
by condensation with readily available 6-amino penicillanic acid

  
or any of the available 7-aminocephalosporin intermediates. Thus, when R6 is the radical:

  

 <EMI ID = 15.1>


  
the compounds described are derivatives of the penicillin series, while

  
 <EMI ID = 16.1>

  

 <EMI ID = 17.1>


  
the derivatives described belong to the cephalosporin series.

  
The nucleus -lactam may remain unsubstituted or may be

  
 <EMI ID = 18.1>

  
Substitution takes place at position 6 in the penicillin series and at position 7 in the cephalosporin series.

  
Position 3 of penicillin and position 2 of

  
cephalosporin are both substituted by a carboxylic acid or carboxylic ester group represented by the formula -COOR7 When R7 is hydrogen, penicillanic or cephalosporanic acids are obtained

  
 <EMI ID = 19.1>

  
alkanoylaminomethyl, alkoxycarbonylaminomethyl and p-alkanoyloxybenzyl.

  
These esters give the molecule excellent absorption properties and at the same time they are physiologically labile. Thus, these esters are easily absorbed in the gastrointestinal tract and hydrolyzed by enzymatic action to the corresponding penicillanic or cephalosporanic acids thus giving excellent oral activity.

  
Certain specific variations in the cephalosporin series are further indicated by the symbol X. Thus, when X is hydrogen, the compounds are deatoxycephalosporanic acids; and when X is a hydroxy group, the compounds are deacetylcephalosporanic acids. When X represents an acetoxy radical, the P-lactam nucleus is that of cephalosporanic acid. Other substituents at position 3 of decephalosporanic acid, which form part of the invention

  
 <EMI ID = 20.1>

  
thiadiazol-1,3,4 yl-2 thio and methyl-1 tetrazol-1,2,3,4 yl-5 thio.

  
Pharmaceutically acceptable salts of the compounds of formula (I) above include the non-toxic carboxylates formed

  
with any suitable inorganic or organic bases. There may be mentioned, for example, the salts of alkali metals, for example sodium and potassium, the salts of alkaline earth metals, such as calcium and magnesium, the salts of light metals of group IIIA, including aluminum, and the salts of primary, secondary and tertiary amines, for example trialkylamines such as triethylamine, procaine, dibenzylamine, vinylamine,

  
N, N'-dibenzylethylenediamine, dihydroabietylamine, N- (lower alkyl) -piperidines and other amines which are used to form

  
non-toxic salts with benzylpenicillin. These salts can be prepared by conventional techniques, such as contacting and neutralizing a solution of the carboxylic acid in a polar solvent with a stoichiometric amount of a base.

  
The pharmaceutically acceptable salts according to the invention also comprise the addition salts of organic or inorganic acids of the basic compounds of: formula (I) above. As examples of inorganic acids forming suitable salts, there may be mentioned hydrochloric, hydrobromic, sulfuric and phosphoric acid as well as

  
acidic salts, such as sodium monohydrogen-orthophosphate and potassium hydrogensulfate. As examples of organic acids forming suitable salts, mention may be made of mono, di and tricarboxylic acids,

  
for example, acetic acid, glycolic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, glutaric acid, fusaric acid, malic acid, tartaric acid, citric acid, ascorbic acid, maleic acid, hydroxymaleic acid, benzoic acid, p acid -hydroxybenzoic acid, phenylacetic acid, cinnamic acid, salicylic acid, 2-phenoxybenzoic acid and sulfonic acids, such as methanesulfonic acid and 2-hydroxyethanesulfonic acid. These salts can exist either in hydrated form or in substantially anhydrous form.

  
Besides the non-toxic addition salts of acids or bases, the pharmaceutically acceptable salts according to the invention also comprise the internal salts or zwitterions of the compounds of formula (I) which

  
 <EMI ID = 21.1>

  
exist as dipolar ions, especially when in solution.

  
As examples of characteristic basic compounds represented by formula (I) above, the following compounds may be mentioned:

  
 <EMI ID = 22.1>

  
/ &#65533;-( 2-chloro-4-oxo-quinolinino) -acetamido7-6 N-ethoxycarbonyl N-methylaminomethyl penicillanate, <EMI ID = 23.1>

  
 <EMI ID = 24.1>

  
isopropoxymethyl, <EMI ID = 25.1>

  
pivaloyloxymethyl,

  
/ a- (oxo-4 pyridino) -acetamido7-7 (pyridiniummethyl) -3 deccephalosporanate,

  
 <EMI ID = 26.1>

  
methyl) -3 deccephalosporanate;

  
/ â- (4-oxo quinoline) -acetamido7-7 (pyridiniummethyl) -3 deccephalosporanate,

  
 <EMI ID = 27.1>

  
 <EMI ID = 28.1>

  
thiadiazol-1,3,4 yl-2) -thiomethyl7-3 decephalosporanate of N-ethoxycarbonyl N-methylaminomethyl,

  
 <EMI ID = 29.1>

  
yl-5) -thiomethyl7-3 decephalosporanic, <EMI ID = 30.1>

  
tetrazol-1,2,3,4 yl-5) -thiomethyl7-3 deccephalosporanic,

  
/ a- (4-oxo pyridino) -acetamido7-7 / Zmethyl-1 tetrazol-1,2,3,4 yl-5) -thio-

  
 <EMI ID = 31.1>

  
7-methoxy / & - (5-trifluoromethyl oxo-4 quinolinino) a-ethylacetamid [pound] p-acetoxybenzyl 7-7 deacetoxycephalosporanate,

  
 <EMI ID = 32.1>

  
The products according to the invention are prepared by reaction of a P-lactam of the 6-amino penicillanic or 7-amino cephalosporanic acid type or its derivative of formula:

  

 <EMI ID = 33.1>


  
with a 4-oxo-pyridinoacetic acid of the formula:

  

 <EMI ID = 34.1>


  
 <EMI ID = 35.1>

  
defined previously.

  
The starting 9-lactams (III) are all known compounds. The 6-amino penicillanic acid can be prepared with the formula:

  

 <EMI ID = 36.1>


  
using biological techniques and also by hydrolysis of various penicillins, as described in United States Patent No. [deg.] 3,499,909.

  
The hydrolysis of cephalosporin C leads to the formation of 7-amino cephalosporanic acid of the formula:

  

 <EMI ID = 37.1>


  
as described by Loder et al., Biochem. J. 79, pages 408-416 (1961).

  
The 7-amino-deacetoxycephalosporanic acid of the formula is prepared:

  

 <EMI ID = 38.1>


  
by catalytic reduction of cephalosporin C, then elimination by hydrolysis of the 5-amino-adipoyl side chain, as described in US Pat. No. 3,129,224.

  
The starting P-lactams of formula (III) above,

  
 <EMI ID = 39.1>

  
in U.S. Patent No. [deg.] 3,778,432.

  
Treatment of cephalosporin C with acetyl esterase prepared from orange peel, Jeffery et al., Biochem. J.
81, page 591 (1961), leads to the formation of 3-hydroxymethyl-7-amino decephalosporanic or 7-amino-deacetylcephalosporanic acid of the formula:

  

 <EMI ID = 40.1>


  
Treatment of cephalosporin C with pyridine followed by acid hydrolysis provides 7-amino-pyridiniummethyl-3-deccephalosporanic acid of the formula:

  

 <EMI ID = 41.1>


  
The preparation of this compound is known in the art and described for example in the patent of the United States of America.

  
n * 3,117,126 and British patents n [deg.] 932,644, n [deg.] 957,570 and n [deg.] 959,054.

  
Substituted thio-3-substituted 7-aminocephalosporanic acids can be obtained by reacting 7-aminocephalosporanic acid with the appropriate thiol, as described in US Pat. No. [deg.] 3,516,997. For example, when using 5-methyl thiadiazole-1,3,4

  
 <EMI ID = 42.1>

  

 <EMI ID = 43.1>


  
When using 1-methyl-1,2,3,4-tetrazol

  
 <EMI ID = 44.1>

  

 <EMI ID = 45.1>


  
Α- (4-oxo-substituted pyridino) -acetic acids (II)

  
 <EMI ID = 46.1>

  
potassium hydroxypyridine to effect the condensation and the resulting ester is hydrolyzed to α- (4-oxo-substituted pyridino) -acetic acid (II) with an aqueous base, as illustrated by the following reaction scheme:

  

 <EMI ID = 47.1>


  
A- (substituted 4-oxo-pyridino) -acetic acids (II) can also be prepared directly by reacting a pyridone (II) with chloroacetic acid or a substituted chloroacetic acid (XIV) in the presence of an aqueous base. strong, as indicated in the following reaction scheme:

  

 <EMI ID = 48.1>
 

  
A preferred technique comprises the prior silylation of a (substituted) 4-hydroxypyridine (XI) in the presence of an organic base, such as triethylamine, with a tri- (lower alkyl) halosilane, such as chlorotrimethylsilane. This procedure allows the purification of the silylated intermediate which, in turn, leads to less contaminated 4-oxo-pyridino (substituted) acetic acids (II) and in increased yield.

  
The 4-oxo-pyridino (substituted) acetic acids of formula (II), in which RS is hydrogen, can also be prepared by treating pyrone or a substituted pyrone with glycine in the presence of a base. In this nucleophilic reaction, the pyrone ring is opened, water is removed and the ring is closed with the nitrogen atom of the amino group now included in the pyridine ring. This reaction, which usually takes place at high temperatures for a long time, can be illustrated by the preparation of 2,6-dimethyl oxo-4 pyridino acetic acid (XVI) from 2,6-dimethyl pyrone -4 (XV) according to the following reaction scheme:

  

 <EMI ID = 49.1>
 

  
In general, the derivatives of 6-amino penicillanic or 7-aminocephalosporanic acids according to the invention can be prepared.

  
 <EMI ID = 50.1>

  
lactam (III) as indicated above. The reaction is generally carried out in solution in the presence of a suitable solvent. Suitable solvents include acetone, dioxane, acetonitrile, chloroform, ethylene chloride, tetrahydrofuran, and other readily available inert solvents. The reaction is furthermore generally carried out in the presence of a base, such as a metal carbonate or hydrogen carbonate.

  
 <EMI ID = 51.1>

  
the reaction can vary between -20 [deg.] C to 100 [deg.] C and room temperature or a slightly lower temperature is preferred. The reaction time can vary between 15 min and 36 h depending, of course, on the temperature of the reaction mixture and the reactivity of the particular reagents used. Preferably a period of 1 to 8 hours is used. After the condensation reaction, the reaction products are isolated and collected using standard extraction and crystallization techniques well known from

  
 <EMI ID = 52.1>

  
To facilitate the condensation reaction, we use

  
a condensing agent. One type of condensing agent essentially acts as a dehydrating agent causing acylation and separating water formed during the reaction. These dehydrating condensing agents or dehydrating agents include the following compounds: dicyclohexylcarbodiimide, N-cyclohexyl N-morpholinomethylcarbodiimide, N, N-cyclohexylidene N-cyclohexylamine, N-ethyl phenyl-5 isoxazolium sulfonate-3 and trichloride

  
phosphorus. Dicyclohexylcarbodiimide is a preferred dehydrating agent, especially in the preparation of the cephalosporin series compounds.

  
A second class of condensing agents can be considered to act on the various 4-oxo-pyridinoacetic acids used so as to activate the carbonyl radical of the acetic acid portion of the molecule, forming a reactive intermediate. This intermediary

  
 <EMI ID = 53.1>

  
Suitable reagent equivalents which can be used successfully include acid halides, acid azides, anhydride. mixed with

  
 <EMI ID = 54.1>

  
or the 4-substituted imidazoles, cyanomethyl esters and the corresponding p-nitrophenyl esters.

  
The preparation of a reactive intermediate represents a preferred process for the preparation of the compounds of the invention, and in particular, for the preparation of the cephalosporin derivatives described below. Suitable condensing agents include carbonyl-

  
 <EMI ID = 55.1>

  
to a solution of 4-oxo-pyridino acetic acid at a temperature below room temperature. The reaction mixture is allowed to reach room temperature and the reaction mixture is subjected to reduced pressure to separate the carbon dioxide given off during the formation of the imidazolide. The solution containing the reactive intermediate imidazolide is cooled again and then condensed with the appropriate P-lactam. The condensation is generally carried out at a temperature of 0 [deg.] C to 150 [deg.] C for a period of 1 to 12 h, after which the desired product is collected.

  
using isolation techniques well known to those skilled in the art.

  
For the direct condensation of amino - &#65533; -lactam acid, one can also condense 6-amino penicillanic acid or 7-amino acid.

  
Cephalosporanic suitable in the form of neutral salts or esters. The

  
 <EMI ID = 56.1>

  
example the salts formed with trimethylamine or triethylamine. The

  
esters represented by formula (III) above are those in which

  
the free carboxy group of amino - β-lactam has been suitably esterified. In cases where the ester group is subsequently removed to obtain the free acid, ester groups which are easily removable are preferred.

  
Among the esters easily converted into the corresponding free acids under relatively mild conditions, mention may be made of silyl and stannyl esters. For example, esters can be submitted

  
hydrolysis, solvolysis or nucleophilic exchange without modification

  
of the rest of the molecule. Suitable silylating agents include

  
alkyldisilanes, for example tetramethyldisilazane and hexamethyldisilazane, or bis-trimethylsilylacetamide. Suitable stannylating agents include, for example, bis- / tri- (lower alkyl) -tin7 oxides, such as bis- (tri-n-butyl-tin) oxide; tri- (lower alkyl) -tin hydroxides, such as triethyltin hydroxide; tri- (lower alkoxy) -tin compounds, such as triethoxytin hydroxide; and tri- (lower alkyl) -tin halides, such as tri- (n-butyl) -tin chloride. The resulting silylated or stannylated carboxy group can be regenerated to the free carboxylic acid by treatment with a neutral hydrogen donor. The hydrogen donor is preferably used

  
water or a lower alkanol, for example, ethanol.

  
Another method for the preparation of the compounds of the invention comprises the treatment of an α-haloacetamido-6 penicillin or -7 cephalosporin derivative with a silyloxy-4 pyridine, as illustrated by the following reaction scheme:

  

 <EMI ID = 57.1>


  
 <EMI ID = 58.1>

  
of chlorine.

  
The starting α-haloacetamido - &#65533; -lactams are known compounds previously described in J. Med. Chem. 16, page 1413
(1973), in Belgian patent n [deg.] 758,587 and United States patents n [deg.] 2,941,995 and n [deg.] 3,516,997. The preparation of the 4-silyloxy pyridines is carried out with a suitable silylating agent, as described above. Suitable silylating agents include di- (alkyl <EMI ID = 59.1>

  
di- (lower alkyl) -bromosilanes and tri- (lower alkyl) -bromosilanea, in which the alkyl group contains 1 to 5 carbon atoms, the tetra-

  
 <EMI ID = 60.1>

  
The condensation reaction is generally carried out in an inert solvent, such as chloroform, acetone, methyl chloride, dimethylformamide, dioxane or acetonitrile. The reaction temperature can vary between -20 [deg.] C and 100 [deg.] C; a temperature of 20 [deg.] C is preferred. The reaction usually takes place in an inert atmosphere, such as nitrogen, argon or helium. The reaction is generally carried out for a period of 15 min to 36 h, depending on the nature of the reagents and the temperature at which the reaction is carried out. The reaction is usually completed within 1 to 24 hours within the preferred temperature range.

  
In general, one equivalent of the 4-ailyloxy-pyridine derivative is reacted with one equivalent of the α-haloacetamido-Plactam derivative. The 9-lactam derivative can also be used in the form of a salt, for example the sodium, triethylamine, N, N-diethylaniline or diisopropylethylamine salt. The P-lactam can also be used in ester form. Esters include those from which the ester group can be easily removed to regenerate the free acid under mild conditions without modifying the rest of the molecule. Mention may be made in particular of tert-butyl esters, trialkylsilyl and trialkylstannyl esters in which the alkyl group contains from 1 to 5 carbon atoms and benzyl esters, preferably trialkylsilyl esters.

   These esters can be readily hydrolyzed to free acids by treatment with a neutral hydrogen donor, such as an alcohol.

  
In all of the above-mentioned condensation reactions, compounds of the invention having reactive functional groups, which may interfere with the condensation reaction, are protected by means of suitable protecting groups. Thus, the carboxy groups located on the pyridone-4 ring of the molecule or on the acetic acid portion of the molecule can be silylated or esterified with other labile ester groups as previously described. Similarly, the amino and hydroxy groups located on the pyridone-4 moiety

  
of the molecule can be suitably protected in the form of labile derivatives. These derivatives include silyl ethers, benzyl ethers and carbonic esters for hydroxy groups, carbobenzyloxy, carbo-tert-butyloxy and triphenylmethyl derivatives for amino groups.

  
Another route leading to cepahlosporin derivatives of formula (I), in which the symbol X represents a (5-methyl-thiadiazol-1,3,4 yl-2) -thio or (1-methyl-1,2-tetrazole, 3,4 yl-5) -thio, consists in the displacement of the acetoxy group located on the methyl group

  
 <EMI ID = 61.1>

  
as illustrated in the following two reaction schemes:

  

 <EMI ID = 62.1>
 

  
 <EMI ID = 63.1>

  
previously.

  
The cephalosporanic acids of formula (XIX) are dissolved with 2-mercapto-5-methyl-1,3,4-thiadiazole (XX) or its metal salt in an inert solvent. Preferably an alkali metal salt of cephalosporanic acid (XIX) is used. These salts can be prepared, for example, by treating cephalosporanic acid with an alkali metal bicarbonate. The reaction is carried out in water or in an aqueous organic solvent, such as aqueous acetone, aqueous tetrahydrofuran or aqueous dimethylformamide. If desired, the pH of the reaction mixture can be adjusted by the addition of aqueous buffers. If free cephalosporanic acids are used as the starting materials, the reaction can be carried out in the presence of a base, such as sodium bicarbonate, triethylamine or potassium bicarbonate.

  
The reaction can take place over a range of temperatures

  
 <EMI ID = 64.1>

  
can be carried out in the presence of an inert gas, such as nitrogen or argon. The reaction time can vary from 15 min to 24 h, preferably from 15 min to 6 h.

  
 <EMI ID = 65.1>

  
position 3 causes migration of the double bond to position 2

  
of the 9-lactam nucleus. Under these circumstances, the position of the double bond can be restored by oxidizing the sulfur of the nucleus to the sulfoxide group with oxidizing agents, such as hydrogen peroxide, sodium metaperiodate or an organic peracid. The subsequent reduction of the sulfoxide by catalytic hydrogenation or by sodium dithionite leads to the derivatives

  
 <EMI ID = 66.1>

  
The new compounds of the invention are biologically active and have been found to have good antibacterial activity. Thus, they constitute useful antimicrobial agents having a broad spectrum of antimicrobial activity in vitro against standard laboratory microorganisms which are used to determine activity against pathogenic bacteria. The antibacterial spectrum of the characteristic compounds of the invention is determined in a conventional manner by the technique of dilution on an agar plate commonly used for the tests of new antibiotics.

  
The presence of the methoxy-7 substituent in the cephalosporin series has a beneficial effect broadening the spectrum of antimicrobial activity against certain gram-negative microorganisms. More particularly, compounds containing the 7-methoxy substituent are active against certain gram-negative microorganisms and are resistant to compounds not containing the 7-methoxy substituent, for example, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens and Proteus species giving a positive indole test.

  
The high in vitro antibacterial activity of the novel compounds of the invention makes them useful, not only as pharmacological agents, but also as feed additives for animals and also as additives for substances subject to microbial deterioration, for example cutting oils. and fuel oils. These compounds are also useful for their antibacterial effect in soaps, shampoos and topical compositions for the treatment of burns and wounds.

  
The following examples illustrate the invention without, however, limiting its scope.

  
EXAMPLE 1

  
4-oxo-pyridino acetic acid.

  
A suspension of 19.0 g (0.2 mol) of 4-hydroxypyridine, 22.2 g (0.22 mol) of triethylamine and 300 ml of toluene is heated to reflux and 23 g ( 0.2 mol) of chlorotrimethylsilane. The mixture is heated with stirring at its reflux temperature for
18 h and filtered. The filtrate is evaporated and the residue is distilled under

  
 <EMI ID = 67.1>

  
9 g (0.054 mol) of the 4-trimethylsiloxy pyridine was mixed with 25 ml of ethyl bromoacetate and the mixture was stirred until the exothermic reaction subsided. The solidified mixture is triturated with ether and filtered. The solid is recrystallized from isopropyl alcohol to obtain 8 g of ethyl 4-oxo-pyridino acetate hydrobromide, mp 195 [deg.] C.

  
8 g (0.03 mol) of the hydrobromide of the ester are added

  
 <EMI ID = 68.1>

  
The mixture is stirred for 5 h, acidified and evaporated to 20 ml. The solution was cooled and filtered to obtain 3.7 g of 4-oxo-pyridinoacetic acid, mp 265-266 [deg.] C.

  
By following substantially the same procedure, but

  
using 3-methyl-4-pyridinol, 2,5-dimethyl-4-pyridinol, 3-nitro-4-pyridinol in place of the above-4-pyridinol, 3-methyl-4-oxo-4-pyridino acid is obtained acetic acid, 2,5-dimethyl oxo-4 pyridino acetic acid and 3-nitro-4 oxo-4 pyridino acetic acid, respectively.

  
EXAMPLE 2

  
4-oxo-quinolinacetic acid.

  
20 g (0.2 mole) of 4-hydroxyquinoline trihydrate are dissolved in a 50% aqueous solution of potassium hydroxide and 20 g (0.2 mole) of chloroacetic acid are added in portions. The resulting solution is refluxed for 18 h, cooled, acidified.

  
and filtered to obtain 7 g of 4-oxo-quinolinacetic acid, mp 278-279 [deg.] C.

  
By following substantially the same procedure, but

  
replacing the above 4-hydroxyquinoline trihydrate with 3-cyano-2,6-dimethyl pyridinol-4, 5-chloro-2-ethoxy-4-pyridinol or 3-trifluoromethyl-4-pyridinol, one obtains 3-cyano-2,6-dimethyl-oxo-4 acid

  
pyridino acetic acid, 5-chloro-2-ethoxy-4-oxo-4-oxo-pyridino-acetic acid and 3-trifluoromethyl-3-oxo-4-pyridino-acetic acid, respectively.

  
EXAMPLE 3

  
2,6-Dimethyl oxo-4 pyridino acetic acid.

  
12.4 g (0.1 mol) of 2,6-dimethyl pyrone-4 are added

  
to a solution of 20 g (0.2 mole) of triethylamine and 7.5 g (0.1 mole) of glycine in a mixture of 100 ml of ethanol and 10 ml of water. The mixture is heated under reflux for 4 days, cooled, acidified and

  
filter to obtain 4 g of 2,6-dimethyl-4-oxo-pyridinoacetic acid,

  
F. 243 [deg.] C.

  
By following substantially the same procedure, but

  
replacing the 2,6-dimethylpyrone-4 above with 3-methoxy-2-methylpyrone-4, 3-hydroxy-4-pyrone and 2,6-dicarbethoxy-4-pyrone, the acid is obtained 3-methoxy 2-methyl-4-oxo-pyridino acetic acid, 3-hydroxy acid

  
4-oxo-pyridino acetic acid and 2,6-dicarbethoxy-4-oxo-pyridino acetic acid, respectively.

  
EXAMPLE 4

  
 <EMI ID = 69.1>

  
Room temperature. Vacuum the reaction flask for 30 min to remove carbon dioxide and cool to -20 [deg.] C. In a separate flask, the silylation of 7-aminocephalosporanic acid is carried out by heating a suspension of 5.4 g (0.02 mole) of 7-aminocephalosporanic acid and 8 ml of hexamethyldisilazane in 50 ml of chloroform. at reflux for 30 min. This solution is evaporated to dryness in order to separate the ammonia liberated. A solution of the residue in 50 ml of chloroform is cooled to -20 [deg.] C and added to the imidazolide. The reaction mixture was stirred at 0 [deg.] C for 1 h, warmed to room temperature and

  
one agitates during one night.

  
The solution is treated with 2 ml of methanol and the precipitated 7-aminocephalosporanic acid is filtered off. 10 ml of a solution of 2N sodium 2-ethyl hexanoate in n-butanol are added and the mixture is diluted with ether to a volume of about 1 liter to precipitate the product. After reprecipitation in methanol with ether,

  
 <EMI ID = 70.1>

  
as a white solid, mp 180 [deg.] C (decomposition). Titration with iodine indicates a purity of 72.7%.

  
By repeating substantially the same procedure, but replacing the above 7-aminocephalosporanic acid with 6-amino-penicillanic acid, 7-amino-deacetylcephalosporanic acid,

  
 <EMI ID = 71.1>

  
respectively.

  
EXAMPLE 5

  
 <EMI ID = 72.1>

  
A solution of 4.1 g is placed under a nitrogen atmosphere.
(0.02 mole) of quinolone-4 acetic-1 in 50 ml of dimethylformamide, cooled to 10 [deg.] C and added, in one portion, 3.2 g (0.02 mole) of carbonyldiimidazole After having warmed the mixture to room temperature, the flask is evacuated for 15 min to separate the carbon dioxide given off in the formation of the imidazolide. The solution is cooled to 10 [deg.] C and a solution of 4.4 g (0.02 mol) of acid is added.

  
 <EMI ID = 73.1>

  
of chloroform. The reaction mixture was stirred at 10 [deg.] C for 1 h, warmed to room temperature and further stirred for 3 h.

  
10 ml of a 2N solution of 2N sodium ethyl hexanoate in butanol are added and the product is precipitated by the addition of 700 ml.

  
 <EMI ID = 74.1>

  
it is reprecipitated with methanol and ether and dried under vacuum to obtain 4.8 g of a white solid, mp 204 [deg.] C (decomposition). Titration with iodine indicates a purity of 86.4%.

  
By repeating substantially the same procedure, but replacing the above quinolone-4 acetic acid-1 with 2,5-dimethyl-4-pyridone-1-acetic acid, 3-nitro-4-pyridone-1-acetic acid, 3-hydroxy-4-pyridone-1-acetic acid and 3,5-diiodo-4-pyridone-1-acetic acid,

  
 <EMI ID = 75.1>

  
sodium, respectively.

  
By replacing the above 6-amino penicillanic acid with 7-amino-7-methoxy cephalosporanic acid, the sodium salts of the following acids are obtained:

  
/ â- (4-oxo-quinolinino) -acetamido7-7 cephalosporanic acid, / â- (2,5-dimethyl-4-oxo-pyridino) -acetamido7-7-methoxy-7 cephalosporanic,

  
 <EMI ID = 76.1>

  
cephalosporanic acid, / a- (3-hydroxy oxo-4 pyridino) -acetamid [pound] 7-7 7-methoxy-cephalosporanic acid, and

  
 <EMI ID = 77.1>

  
cephalosporanic methoxy-7.

  
EXAMPLE 6

  
 <EMI ID = 78.1>

  
3.6 g (0.02 mole) of 2,6-dimethyl-4-pyridone-1-acetic acid are dissolved in 50 ml of dimethylformamide and the solution is cooled to 0 [deg.] C. 3.2 g (0.02 mole) of carbonyldiimidazole are added and the mixture is stirred under a nitrogen atmosphere at 0 [deg.] C for 30 min, then it is allowed to warm to room temperature. The reaction flask is evacuated for 30 min to separate the evolved carbon dioxide. The resulting solution was cooled to -20 [deg.] C and a solution of 0.02 mole trimethylsilyl 7-aminocephalosporanate prepared as in Example 4 above in 50 ml of chloroform was added. The reaction mixture was stirred at 0 [deg.] C for 1 h, warmed to room temperature and stirred overnight.

  
The reaction mixture is treated with 2 ml of methanol and the precipitated 7-aminocephalosporanic acid is filtered off.

  
10 ml of a solution of 2N sodium 2-ethyl hexanoate in n-butanol are added to the reaction mixture, diluted to 1 liter with ether and filtered.

  
 <EMI ID = 79.1>

  
4-oxo-pyridino) -acetamido7-7 cephalosporanic thus obtained and dried under vacuum to obtain 5.0 g of white powder, mp 240 [deg.] C.

  
By following substantially the same procedure, but

  
replacing 2,6-dimethyl-4-pyridone-1-acetic acid with 3-methyl-4-pyridone-4-acetic acid, 5,6,7,8-tetrahydro-5,6,7,8 quinolone-4-acetic acid 1, 5-chloro-2-ethoxy-4-pyridone-1-acetic acid, 3-trifluoromethyl-4-pyridone-1-acetic acid, and 3-hydroxy-3-pyridone-4

  
 <EMI ID = 80.1>

  
By substituting the above 6-amino-6-methoxy-trimethylsilyl penicillanate for the 7-amino-trimethylsilyl cephalosporanate, the sodium salts of the following acids are obtained:

  
/ a- (2,6-dimethyl oxo-4 pyridino) -acetamido7-6-methoxy-6 penicillanic acid,

  
 <EMI ID = 81.1>

  
6-methoxy penicillanic acid.

  
EXAMPLE 7

  
 <EMI ID = 82.1>

  
sodium sporanate in water and reacted with pyridine in the presence of potassium thiocyanate at 60 [deg.] C for 6 h. We operate on the bark

  
 <EMI ID = 83.1>

  
sporanate in the form of the zwitterion.

  
EXAMPLE 8

  
 <EMI ID = 84.1>

  
sodium sporanate with an acetylesterase isolated from orange peel as described by J.D'A. Jeffery et al., Biochem. J., 81, page 591 (1961) for

  
 <EMI ID = 85.1>

  
sodium.

  
EXAMPLE 9

  
Trimethylsilyloxy-4 pyridine.

  
To 500 g of crude 4-hydroxy pyridine, 5.5 l

  
toluene. The mixture is heated with stirring and about 700 ml of toluene is distilled to remove any water that may be present. The reaction mixture is maintained at its reflux temperature and slowly added
543 g of trimethylsilyl chloride. The reaction mixture is refluxed for about 3 h, cooled and filtered. The filtrate is evaporated under reduced pressure to separate the toluene and the mixture is distilled.

  
the residue under 18-20 mm to obtain 620 g of trimethylsilyloxy-4 pyridine, E. 95-96 [deg.] C / 18-20 mm Hg.

  
EXAMPLE 10

  
 <EMI ID = 86.1>

  
To 20.0 g of (α-bromoacetamido) -7 cephalosporanic acid prepared according to United States Patent No. [deg.] 3,647,789, 135 ml of chloroform and 20 ml of N, 0- are added. bis-trimethylsilylacetamide. The mixture is stirred for about 1 hour under a dry nitrogen atmosphere and further stirred at room temperature for about 15 hours still under dry nitrogen. 80 ml of methanol are added to the reaction mixture while stirring until all the precipitate initially formed has dissolved. The mixture is poured into about 1 liter of anhydrous ether with stirring, the solvent is separated by decantation and the remaining sticky precipitate is dissolved in a further 400 ml of methanol.

   To the solution containing the dissolved precipitate is added 65 ml of a solution of 2N sodium 2-ethyl hexanoate in n-butanol and the resulting mixture is treated with activated carbon and filtered through a bed of diatomaceous earth. Slowly added to the filtrate
900 ml of isopropyl alcohol. The precipitate formed is filtered off, washed with ether and dried in vacuo to give 17.2 g of

  
 <EMI ID = 87.1>

  
a-methylacetamido) -6 penicillanic acid, (a-bromoacetamido) -6 methoxy-6 penicillanic and (a-bromo a -carbethoxyacetamido) -6 penicillanic acid,

  
 <EMI ID = 88.1>

  
vement.

  
Using 2,6-dimethyltrimethylsilyloxy-4-pyridine and bis- (carbotrimethylsilyloxy) -2,6-trimethylsilyloxy-4-pyridine in

  
the above process, the a- (2,6-dimethyl oxo-4 pyridino) derivatives are obtained,

  
 <EMI ID = 89.1>

  
dants of the various cephalosporanic and penicillanic acids above, in the form of their sodium salts.

EXAMPLE 11

  
 <EMI ID = 90.1>

  
deccephalosporanic.

  
Has 1.4 g of 7-amino acid / 5-methyl-1,3,4-thiadiazole

  
 <EMI ID = 91.1>

  
of the United States of America n [deg.] 3,516,997, 3 g of sodium bicarbonate are added to a stirred mixture of 25 ml of water and 25 ml of acetone. The mixture is cooled to -10 [deg.] C and to the stirred mixture is slowly added 2.2 g of bromide.

  
of bromoacetyl in 1 ml of acetone over 10 min. The mixture is stirred for a further 1 h at -10 [deg.] C and allowed to come to room temperature. The reaction mixture is extracted with ethyl acetate and the organic phase is discarded. The aqueous phase is covered with 100 ml of ethyl acetate and

  
 <EMI ID = 92.1>

  
rique. The organic phase is separated, dried over sodium sulfate and decolorized with charcoal. The solution is filtered, evaporated and the residue is triturated with ether. The residue is dried in vacuo to obtain

  
 <EMI ID = 93.1>

  
/ EXAMPLE 12

  
 <EMI ID = 94.1>

  
a clear solution, 1.6 g of trimethylsilyloxy-4 pyridine are added and the mixture is stirred for 18 h under a nitrogen atmosphere. Ml of methanol are added and the solid precipitate formed is collected by filtration. The precipitate is dissolved in 100 ml of methanol, 5 ml of a solution of 2N sodium 2-ethyl hexanoate in n-butanol and then 200 ml of ether are added. The precipitate formed is collected by filtration and dried in vacuo to obtain

  
 <EMI ID = 95.1>

  
N, N-diethylaniline, one equivalent of 3-cyano-trimethylsilyloxy-4 pyridine is added. The mixture is stirred for about 15 h at room temperature under a nitrogen atmosphere. Methanol then anhydrous ether is added. The precipitate formed is separated by filtration, dissolved in methanol and one equivalent of a butanol solution of 2-ethylhexanoate is added.

  
of 2N sodium. An equal volume of ether is added and the precipitate formed is filtered off and dried in vacuo to obtain the acid / a- (cyano-3

  
 <EMI ID = 96.1>

  
deccephalosporanic sodium salt.

EXAMPLE 14

  
 <EMI ID = 97.1>

  
A mixture of 3.5 g of sodium methoxy-7 / a- (4-oxo-quinolinino) -acetamido7-7 cephalosporanate, 2.5 is heated to approximately 70 ° C. in a nitrogen atmosphere for approximately 4 hours. g of sodium bicarbonate, 2.6 g of 5-methylmercapto-1,2,3,4-tetrazol and 60 ml of water. The reaction mixture is cooled and evaporated under reduced pressure. The remaining residue is triturated with acetone, dissolved in methanol and filtered. We add

  
with isopropyl alcohol filtrate to form a precipitate which is collected by filtration and dried under vacuum to obtain a precipitate

  
 <EMI ID = 98.1>

  
1,2,3,4 yl-5) -thiomethyl7-3 decephalosporanic in the form of sodium salt.

  
By following substantially the same procedure, but

  
 <EMI ID = 99.1>

  
yl-5) -thiomethyl7-3 deccephalosporan, respectively, in the form of their sodium salts.

  
EXAMPLE 15

  
 <EMI ID = 100.1>

  
sodium cephalosporanate in 500 ml of water, 0.95 g of sodium bicarbonate and 2.96 g of 2-mercapto-5-methyl-1,3,4-thiadiazole are added. The mixture is heated under a nitrogen atmosphere at 70 [deg.] C for 3 h and evaporated under reduced pressure. The residue is dissolved in 50 ml of methanol and treated with excess acetonitrile. The white precipitate formed is separated by filtration, washed with acetonitrile and dried in vacuo to obtain

  
 <EMI ID = 101.1>

  
their sodium salts.

  
 <EMI ID = 102.1>

  
of sodium dissolved in 40 ml of dimethylformamide and cooled to 0 [deg.] C, 2.6 g of pivaloyloxymethyl iodide are added and the solution is stirred for about 25 min. The mixture is diluted with 170 ml of ethyl acetate, washed well with water, then washed with dilute sodium bicarbonate solution. The organic phase is dried over anhydrous sodium sulfate and filtered.

  
 <EMI ID = 103.1>

  
pivaloyloxymethyl cephalosporanate.

  
By following substantially the same procedure, but replacing the above pivaloyloxymethyl iodide with acetoxymethyl iodide, N-chloromethyl N-methyl urethane or bromide.

  
 <EMI ID = 104.1> <EMI ID = 105.1>

  
methyl, respectively.

  
EXAMPLE 17

  
 <EMI ID = 106.1>

  
sodium sporanate in 20 ml of dimethylformamide maintained at a temperature of 0-5 [deg.] C, a solution of 0.01 mol of N-chloromethyl N-methylurethane in 5 ml of dimethylformamide is added. The mixture is stirred for about 1 hour and poured into water. The precipitate formed is dissolved in ethyl acetate, washed with water and then with dilute sodium bicarbonate solution and dried over anhydrous magnesium sulfate. The solution is evaporated under reduced pressure to obtain

  
 <EMI ID = 107.1>

  
N-ethoxycarbonyl N-methylaminomethyl methyl 7-3 decephalosporanate.

  
EXAMPLE 18

  
Specific nutrient agar plates are completely inoculated with the various test organisms. Filter paper discs are placed on the agar surface and moistened with 0.1 ml of a solution containing 10, 100 or 1000 µ of the test compound. Areas of inhibition of microbial growth are used to indicate the antibacterial activity of the test compound against the various test organisms used.

  
The table below illustrates the in vitro activity of

  
 <EMI ID = 108.1>

  
acetamido7-6 sodium penicillanate.

  

 <EMI ID = 109.1>


  

 <EMI ID = 110.1>



    

Claims (1)

1 CLAIMS <EMI ID = 111.1> penicillanic or cephalosporanic, characterized in that they correspond to the general formula (I): <EMI ID = 112.1> <EMI ID = 113.1> each a hydrogen or halogen atom, or a hydroxy, lower alkyl, trifluoromethyl, nitro, amino, cyano, carboxy, carbomethoxy group, <EMI ID = 114.1> they are linked to an attached perhydrobenzo or benzo ring, R- is a hydrogen atom or a methyl, carboxy, carbomethoxy or carbethoxy group, R, is a group: <EMI ID = 115.1> <EMI ID = 116.1> 2. Pyridinoacetamido-6 penicillin derivative according to claim 1, characterized in that R. is a radical: <EMI ID = 117.1> and R8 is a hydrogen atom. 3. Derivative of pyridinoacetamido-6 penicillin according to claim 1, characterized in that R6 is a radical: <EMI ID = 118.1> <EMI ID = 119.1> 4. A derivative of pyridinoacetamido-7 cephalosporin according to claim 1, characterized in that R6 is a radical: <EMI ID = 120.1> <EMI ID = 121.1> <EMI ID = 122.1> <EMI ID = 123.1> 6. Compound according to claim 3, characterized in that X is an acetoxy group. 7. A compound according to claim 3, characterized in that <EMI ID = 124.1> 12. Process for the preparation of the compounds according to claim 1, characterized in that it comprises the following steps: (a) a 4-oxo-pyridinoacetic acid of formula is dissolved in a solvent: <EMI ID = 125.1> <EMI ID = 126.1> <EMI ID = 127.1> <EMI ID = 128.1> inert; (b) condensing said pyridinoacetic acid and said P-lactam in solution with dehydration at a temperature of -20 [deg.] C to 100 [deg.] C for a period of 15 min to 36 h in the presence of an agent desiccant selected from dicyclohexylcarbodiimide, N-cyclohexyl N'-morpholinomethylcarbodiimide, N, N-cyclohexylidene cyclohexylamine, N-ethyl phenyl-5 isoxazoliumsulfonate-3 'and phosphorus trichloride; and (c) recovering the desired product from the reaction mixture. 13. Process for the preparation of the compounds according to claim 1, characterized in that it comprises the following steps: (a) reacting a 4-oxo-pyridinoacetic acid of formula: <EMI ID = 129.1> <EMI ID = 130.1> reagent; (b) said pyridinoacetylated intermediate is condensed with an amino-P-lactam of formula: <EMI ID = 131.1> <EMI ID = 132.1> temperature from -20 [deg.] C to 100 [deg.] C for a period of 15 min to 36 h; and (c) recovering the desired product from the reaction mixture. 14. Process for the preparation of the compounds according to claim 1, characterized in that it comprises the following steps: <EMI ID = 133.1> of formula: <EMI ID = 134.1> <EMI ID = 135.1> silylating agent selected from di- (lower alkyl) -chlorosilanes, tri- (lower alkyl) -chlorosilanes, di (lower alkyl) bromosilanes and tri- (lower alkyl) -bromosilanes, in which the lower alkyl group contains 1 to 5 carbon atoms, tetramethyldisilazane, hexamethyldisilazana and bis- (trimethylsilyl) -acetamide to form 4-silyloxy-pyridine; (b) condensing said 4-silyloxy pyridine with an <EMI ID = 136.1> <EMI ID = 137.1> <EMI ID = 138.1> from chlorine, bromine and iodine, in solution at a temperature of -20 [deg.] C to 100 [deg.] C for a period of 15 min to 36 h; and (c) recovering the desired product from the reaction mixture. 15. Method according to any one of claims 12, 13 or 14, characterized in that R6 is the group: <EMI ID = 139.1> 16. Method according to claims 12 and 15, characterized <EMI ID = 140.1> 17. Process according to claims 13 and 15, characterized in that the 4-oxo-pyridinoacetic acid is reacted with carbonyldiimidazole to obtain a 4-oxo-pyridinoacetoimidazolide intermediate. 18. The method of claims 14 and 15, characterized in that the silylating agent is trimethylchlorosilane and Y is a bromine atom. 19. Process for the preparation of the compounds according to claim 1, in which R6 is the group: <EMI ID = 141.1> <EMI ID = 142.1> zole-1,2,3,4 yl-5) -thio, characterized in that it comprises the following steps: <EMI ID = 143.1> formula : <EMI ID = 144.1> <EMI ID = 145.1> aqueous acetone, tetrahydrofuran and dimethylformamide; (b) said solution is reacted at a temperature of 25 [deg.] C to 150 [deg.] C for a period of 15 min to 24 h; and (c) recovering the desired product from the reaction mixture. 20. New medicaments useful in particular as antibacterials, characterized in that they consist of 4-oxo-4-pyridinoacetamido-penicillanic or -7 cephalosporanic acids according to any one of claims 1 to 11 and their pharmaceutically acceptable salts. 21. Germicidal preparations, characterized in that they contain as an antibacterial agent a compound according to any one of claims 1 to 11. 22. Feed additives for animals, characterized in that they consist of compounds according to any one of claims 1 to 11. "New derivatives of 4-oxo-pyridino- penicillins and cephalosporins useful in particular as antibacterials and their preparation process " Please note that the text of the description filed in support of the above patent application should be corrected as follows. : - on page 30, lines 2 and 3, it should read: ", bis- (carbotrimethylsilyloxy) -2.6 trimethylsilyloxy-4 pyridine and 3-chloro-trimethylsilyloxy-4-pyridine in the above process, .. instead of: "and bis- (carbotrimethylsilyloxy) -2.6 trimethylsilyloxy-4 pyridine in the above process, _11 The applicant is aware that no document attached to the file of an invention patent can be of a nature to make, either to the description or to the drawings, substantive modifications and declares that the content of this note no 'make no such changes and has no other purpose than to report one or more material errors. It recognizes that the content of this note cannot have the effect of making the patent N [deg.] PV 0 / 150.295 fully or partially valid if it is not fully or partially valid under current legislation. in force. It authorizes the administration to attach this note to the patent file and to issue a photocopy thereof. Herewith 100, - frs in fiscal stamps for the payment of the tax collected for the notifications of the species. Please accept, Gentlemen, our best regards.