DK151027B - METHOD OF ANALOGUE FOR THE PREPARATION OF 7ALFA-METHOXY-7BETA- (2-AMINOTHIAZOL-4-YLACETAMIDO) CEPHALOSPORINES OR PHARMACEUTICAL ACCEPTABLE SALTS OR ESTERS THEREOF - Google Patents

Description

in 151027

The invention relates to an analogous process for the preparation of novel 7 (x-methoxy-73- (2-aminothiazol-4-ylacetamido) cephalosporins of the general formula NH0 (OCH-ί) La

N_U-CH2CONH- - / N

0J – γ · * (i>

COOH

Wherein R is acetoxymethyl or 1-methyl-1H-tetrazol-5-ylthiomethyl, or pharmaceutically acceptable salts or C1-4 alkoxymethyl-, ot-C1-4 alkoxyethyl-, C1-6 alkylthiomethyl-, C2_5acyloxymethyl- or a-C2_5acyloxy-C2 4 alkyl esters thereof.

The process according to the invention is characterized in that a) a) is reacted with a 7a-methoxycephalosporin derivative of the formula

? CH3 j S

wherein R is as defined above and R is a hydrogen atom or an ester group, or a salt thereof with an aminothiazolyl acetic acid derivative of the formula Ϋ) N-1-CH 2 COOH (III) wherein R 2 is a protected amino group, or a reactive derivative thereof, whereupon removing the ester group and protecting group if necessary, or b) reacting a 7α-methoxycephalosporin compound of Formula 2. p

HalCH2COCH2CONH-Mg-Myl-R (IV> COOR5 wherein Hal is a halogen and R and R5 have the same meanings as above, or a salt thereof with thiourea, where necessary removing the ester group, or c) reacting 7α-methoxycephalosporin derivatives of the formula </ β and 3

ii I i A

N_ll-CH2CONH -.-- S \ o J— \ J-CH2X (VI)

COOH

4 wherein R is an amino group which may be optionally protected and X is an acetoxy or carbamoyloxy group, or a salt thereof with 1-methyl-1H-tetrazole-5-thiol, where necessary removing the protecting group, or dj converts a 7α-methoxycephalosporin compound of the formula OCH-, HOOC jg \ h (CH9) .CONH -, - / \ Γ ..... (VIII) COOCH2CCl3 [COOR5 wherein R and R have the same meanings as above, or a salt thereof with a reactive derivative of an aminothiazolyl-acetic acid derivative of the formula Ϋί J-1 -CH 2 COOH (III ') wherein R 1 - has the same meaning as above, in the presence of a silylating agent to remove the protected amino adipoyl group and necessary the ester group and the protecting group and, if desired, convert an obtained compound of formula (I) into a pharmaceutically acceptable salt or a pharmaceutically acceptable ester thereof.

From Swedish Patent Specification No. 416,553, certain 7α-substituted-7β-acylaminocephalosporanoic acid compounds 10 having antibacterial effect are known, including the commercial product "CEFOXITIN" (3-carbamoyloxymethyl-7α-methoxy-7- [2- (2-thienyl) -acetamido] -3 -cephem-4-carboxylic acid).

It has been found that the compounds of the present invention have a surprisingly good antibacterial effect over the known compounds. This is illustrated in the table below, which lists minimum inhibitory concentrations for the compounds 7a-methoxy-73- (2-aminothiazol-4-yl-acetamido) -3-acetoxymethyl-3-cephem-4-carboxylic acid (A) and 7a. -methoxy-7β- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazol-5-yl-thiomethyl) -3-cephem-4-carboxylic acid (B) and for the known compound "CEFOXITIN".

Table

Microorganism AB Cefoxitin S. aureus 209 P 6.25 1.56 3.13 25 S. aureus 1840 6.25 3.13 3.13 E. coli NIHJ JC-2 3.13 1.56 6.25 E. coli 0-111 1.56 0.78 3.13 E. coli T-6.25 6.25 25 K. pneumoniae DT 3.13 0.78 3.13 30 p. Vulgaris Eb 58 6.25 1.56 6.25 P. morganii Eb 53 12.5 3.13 12.5

Ps. aeruginosa U 31> 100> 100> 100 S. marcescens IFO 12648 12.5 6.25 25

C c-i - 1- = 4 - i => ΦνΠΛ OA OH C OK C OK

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The compounds of formula (I) can be used with the free-form 4-carboxylic acid function. They may also be used as pharmaceutically acceptable salts, e.g. salts of sodium, potassium, basic amino acids, e.g. arginine, ornithine, lysine 5 and histidine, and polyhydroxyalkylamines, e.g. N-methyl-glucamine, diethanolamine, triethanolamine and tris-hydroxy-methylaminomethane. The compounds (I) can also be used with their 4-carboxyl group converted to a biologically active ester derivative, e.g. leads to an increased blood level and a prolonged effect. Ester residues favorable for this purpose are C er3alk alkoxymethyl groups or α-C1_alkoxyethyl groups such as mefchoxymethyl, ethoxymethyl, isopropoxyethyl, α-methoxyethyl and α-ethoxyethyl, C · ^3 alkyl thiomethyl groups such as methylthiomethyl, ethylthiomethyl and isopropylthiomethyl and C2-5acyloxymethyl groups or aH3 acyloxy-C2-4 alkyl groups such as pivaloyloxymethyl and α-acetoxybutyl.

The compounds of the invention may be in two tautomeric forms as shown below, but in this description the compounds in thiazole form, i.e. formula (I):

mo / Sv AND NHv .S. OCEL

V \: 3 V \: 3

II: A, 1: A

ir.-1-ch2cohh -: _ / \ - ^ m — 1-ch2conh- * .v \ ^ —ir. J-h J — ir J-R · 20 y 0y y

(j) C00H C00H

Compounds (I) have a wide antimicrobial spectrum, i. activity against gram-negative and gram-positive bacteria, and in particular exhibit greater activity than the known cephalosporins against antibiotic resistant strains of such gram-negative bacteria as Escherichia coli, Serratia marcescens and Proteus vulgaris. The compounds (I) are therefore useful for treating infections with the above bacteria in humans and animals and provide excellent therapeutic results. Similar to the known cephalosporin drugs, the compounds of this invention can be administered to patients e.g.

5 by injection or as capsules, tablets and granules and if necessary together with physiologically acceptable carriers or excipients, e.g. as solutions, suspensions or solid preparations.

Eg. For example, sodium 7α-methoxy-73- (2-aminothiazol-4-ylacet-10-amido) -3- (1-methyl-1H-tetrazol-5-ylthiomethyl) -3-cephem-4-carboxylate can be administered intramuscularly in a daily dose of about 5-20 mg per day. kg of body weight in three to five separate doses daily, and this therapy is particularly effective in treating respiratory and urinary tract infections.

In process a) the starting compound (II) with the 4-carboxyl group present is used in the form of an alkali metal salt or a salt with an organic amine, e.g. the sodium, potassium or triethylamine salt, or in the form of an ester which can be converted to a free carboxyl group under mild conditions, e.g. by the action of acid or alkali or by reduction. The ester group can e.g. be β-methylsulfonylethyl, trimethylsilyl, dimethylsilenyl, benzhydryl, β, β, β-trichlorethyl, phenacyl, p-methoxybenzyl, p-nitrobenzyl or methoxymethyl, in the starting material (III), an amino group protected with a readily removable amino protecting group used in general peptide chemistry, e.g. t-butoxycarbonyl, p-nitrobenzyloxycarbonyl, β, β, β-trichloroethoxycarbonyl, benzyloxycarbonyl or isobornyl-oxycarbonyl, or with proton. The reactive derivative of the starting compound (III) can be e.g. be an acid halide, acid anhydride, mixed acid anhydride, an active amide or active ester. Usually, this reaction can be carried out smoothly and advantageously in a solvent. The solvent is one which does not affect the reaction, e.g. acetone, tetrahydrofuran, dioxane, acetonitrile, chloroform, dichloromethane, dichloromethylene, pyridine, dimethylaniline, dimethylformamide, dimethylacetamide, dimethylsulfoxide or mixtures of such solvents. Although there is no particular restriction on the reaction temperature, reaction 5 is usually carried out under cooling or at room temperature. If necessary, the protecting group is removed from the resulting 7-methoxycephalosporin derivative to obtain a 7-methoxycephalo-sporin derivative of the general formula (I). As for the removal of protecting groups, e.g. t-butoxy-10 carbonyl by acid, 3, β, β-trichloroethoxycarbonyl by reduction using zinc and acid and p-nitro-benzyloxycarbonyl by catalytic reduction. As for the removal of the ester group from the 4-carboxyl group, e.g. benzhydryl, p-methoxybenzyl by acid; β-15 methylsulfonylethyl by base; trimethylsilyl, dimethylsilenyl by water alone; β, β, β-trichloroethyl by reduction using zinc and acid and p-nitrobenzyl by reduction. The removal of these protecting groups can be performed simultaneously or successively. Which 20 protecting group to remove first is determined by the nature of the protecting groups, the subsequent reaction and other factors.

In process b) the reaction proceeds smoothly in a solvent, e.g. any ordinary solvent which does not interfere with the desired reaction, e.g. water, methanol, ethanol, acetone, dioxane, acetonitrile, chloroform, ethylene chloride, tetrahydrofuran, ethyl acetate, dimethylformamide, dimethylacetamide or a mixture of such solvents. Although the addition of an acid binding agent is not essential, there are cases where the reaction proceeds more smoothly in the presence of an acid binding agent, provided that the addition of that agent does not alter the cephalosporin core. As an acid binding agent for this purpose may be mentioned inorganic and organic bases such as alkali metal hydroxides, alkali metal hydrogen carbonates, triethylamine, pyridine and N, N-dimethylaniline. The starting compound (IV) is reacted in the form of the free acid, an alkali metal salt, e.g. the sodium or potassium salt, or an ester such as those mentioned above in connection with the 4-carboxyl group. Usually, the reaction proceeds smoothly at room temperature, but if necessary it can be carried out under heating or cooling.

The starting compound (IV) used in process b) can be obtained by reacting a 7-aminocephalosporin compound (II) with a 4-halogen-3-oxo-butyryl halide, which can be obtained by reacting the diket with a halogen such as chlorine or bromine. (Journal of the Chemical Society 92/1987 (1910)).

In process c), the compounds (VI) are usually reacted in the form of sodium or potassium salts or another salt of the 4-carboxyl function.

Although the 1-methyl-1H-tetrazole-5-thiol may be used in free form, it may advantageously be used as an alkali metal salt, e.g. sodium or potassium salt. This reaction is preferably carried out in a solvent. For this purpose, e.g. water, heavy water or an organic solvent which is readily miscible with water and which does not participate in the reaction, e.g. dimethylformamide, dimethylacetamide, dioxane, acetone, alcohol, acetonitrile, dimethylsulfoxide and tetrahydrofuran. The reaction temperature and time depend, inter alia, on of the actual materials and solvent used, but can generally be selected in the range of 25 ° C to 100 ° C and in the range of a few hours to separate even days, respectively. The reaction is preferably carried out near the neutral point, i.e. at pH 2-8 and to achieve even better results at pH 5-8. This reaction can sometimes be made more smooth by the addition of a quaternary ammonium salt with surface activity, e.g. trimethylbenzyl ammonium bromide, triethylbenzylammonium bromide or triethylbenzylammonium hydroxide, for the reaction system. More satisfactory results can be obtained by carrying out the reaction in an atmosphere of an inert gas, e.g. nitrogen, to prevent atmospheric oxidation of the thiol.

8 151027

In process d), the 4-carboxyl group in the starting material (VIII) can be free or esterified as in the case of compound (II) above, insofar as the current ester is not detrimental to the intended reaction. The reaction is carried out in a suitable solvent and in the presence of a silylating agent such as a trisubstituted silyl derivative of an electronegatively substituted amide. The reaction proceeds smoothly at a temperature of -20 to 50 ° C, usually in the range of 15-45 ° C. The solvent may e.g. be chloroform, dichloromethane, acetonitrile or dioxane.

The above negatively substituted trisubstituted silyl derivative is a compound prepared by reacting an electronegatively substituted amide or imide with a trisubstituted silyl halide. As amide or imide may be mentioned succinimide, phthalimide, cyanoacetamide, trifluoroacetamide and trichloroacetamide. Particularly useful for the desired reaction are N-trimethylsilyltrifluoroacetamide and N-trimethylsilyl phthalimide. The resulting reaction product, as it occurs in the reaction mixture or after a suitable treatment, such as concentration or isolation, is subjected to a reaction which leads to removal of the protected aminoadipoyl group. This reaction is usually carried out under similar conditions as those used to remove β, β, β-trichloroethoxy-carbonyl. It thus consists, for example, in reaction with zinc and 25 aqueous acetic acid or aqueous formic acid. The reaction can usually be carried out satisfactorily at room temperature, the range of 10-40 ° C being useful.

The compounds (I) obtained by the methods described above can be purified by procedures known per se, e.g. column chromatography, extraction, precipitation and recrystallization.

The aminothiazolylacetic acid derivatives (III) can e.g. is prepared by reacting a chloroformic acid haloethyl ester with thiocyanate to form a 2-haloethoxycarbonyl isothiocyanate, reacting the thus obtained compound with ammonia to form an N- (2-haloethoxycarbonyl) thiourea, reacting the compound with -haloacetic acid alkyl ester to form a 2- (2'-haloethoxycarbonyl-5-amino) -thiazol-4-ylacetic acid alkyl ester and hydrolyzes the alkyl ester to give a 2- (21-halo-ethoxy-carbonyl-amino) -thiazol-4-yl-acetic acid . Alternatively, 2- (2'-halo-ethoxy-carbonylamino) -thiazol-4-ylacetic acid can be prepared by reacting a 2-aminothiazol-4-ylacetic acid alkyl ester 10 with a chloroformic acid-2-haloethyl ether and hydrolyzing the 2- ( 2'-haloethoxycarbonylamino) -thiazol-4-ylacetic acid alkyl ester.

For example, the halogen substituting the 2-position of the ethyl group in the chloromyric acid ethyl esters may be used. may be chlorine, bromine and / or fluorine and 1-3 such halogen atoms may be present as substituents. Thus, common trichloro, dibromo and other compounds are used. For this purpose, thiocyanic acid can be used in its free form, but usually it is more conveniently reacted as one of the salts with alkali metals, e.g. sodium or potassium, salts with heavy metals, e.g. copper or lead, or as the ammonium salt. This reaction proceeds smoothly in a solvent. The solvent normally used is preferably non-protonic solvent such as acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, acetonitrile, ether, benzene or toluene. Advantageously, the reaction is carried out at a low temperature to avoid unwanted side reactions. Usually, the reaction can be carried out smoothly within a range of from 5 to -20 ° C.

The 2-haloethoxycarbonyl isothiocyanate thus obtained is so reactive that it is not normally isolated, but the reaction mixture as such is subjected to the next treatment, i.e. reaction with ammonia to form an N- (2-haloethoxycarbonyl) thiourea. This ammonia addition reaction can be carried out by introducing ammonia into the reaction mixture obtained by the above-mentioned preparation step for 2-halo-genethoxycarbonyl isothiocyanate, but normally the metal halide or ammonium halide formed as a by-product is separated from the 2-haloethyl ester and a thiocyanate salt first by filtration, and then ammonia is introduced into the filtrate. The ammonia may be added in the gaseous state or a solution of ammonia may be introduced into a suitable solvent, e.g. methanol or ethanol. The reaction is preferably carried out at a low temperature, usually in the range of 5 to -10 ° C.

The reaction of a ω-haloacetoacetic acid compound with an N- (2-trichloroethoxycarbonyl) thiourea to form a 2- (2'-trichloroethoxycarbonylamino) -thiazol-4-ylacetic acid is usually advantageously carried out in a solvent and in the presence of a base. The solvent may be any one which is capable of dissolving the two starting materials and which at the same time does not interfere with the desired reaction. Thus, for example, employ alcohols such as methanol, ethanol, propanol, ketones such as acetone, methyl ethyl ketone, ethers such as ethyl ether, tetrahydrofuran, dioxane and mixtures thereof. This reaction proceeds smoothly in the presence of a base.

As bases, e.g. mention is made of organic tertiary bases such as pyridine, picoline, guinoline, isoquinoline, triethylamine, tri-butylamine, N-methyl-piperidine, N-methyl-morpholine, N, N-dimethylaniline and Ν, diet-diethylaniline. The reaction proceeds at room temperature, but there are cases where the reaction is accelerated by heating. A heating temperature near the boiling point of the solvent used is usually advantageous. As ω-haloacetoacetic acid alkyl ester, e.g. methyl m-chloroacetoacetate, ethyl m-chloroacetoacetate, methyl co-bromoacetoacetate or ethyl m-bromoacetoacetate are used.

The reaction of a 2-aminothiazol-4-ylacetic acid alkyl ester with 2-trichloroethyl chloroformate to form a 2- (21-halo-ethoxycarbonylamino) -thiazol-4-ylacetic acid alkyl ester is usually carried out smoothly in a solvent and in the presence of a base.

The solvent may be any that does not interfere with the desired reaction. Typically, a non-protonic organic solvent such as chloroform, dichloromethane, dichloroethylene, carbon tetrachloride, chlorobenzene, ether, tetrahydrofuran, dioxane, acetone or methyl ethyl ketone, or a mixture of such solvents is used. The base may be any such that is able to absorb or reconcile with the hydrogen halide formed during the reaction and which does not interfere with the reaction. Thus, organic tertiary bases such as pyridine, picoline, quinoline, isoquinoline, triethylamine, tri-butylamine, N-methylpiperidine, N-methylmorpholine, N, N-dimethylaniline or Ν, diet-diethylaniline can normally be used. Although the reaction proceeds smoothly at room temperature, the reaction system may optionally be cooled or heated.

The 2- (2'-haloethoxycarbonylamino) -thiazol-4-ylacetic acid ester thus obtained is partially hydrolyzed to a 2- (2'-haloethoxycarbonylamino) -thiazol-4-ylacetic acid. This hydrolysis reaction is carried out in a solvent and in the presence of a base. Preferably, the solvent is one capable of dissolving both the ester used as the starting material and the base. Thus, a mixture of water and an organic solvent miscible with water such as ethanol or acetone is usually used. As a base, an inorganic strong base such as sodium hydroxide, potassium hydroxide or barium hydroxide is normally used. This reaction is advantageously carried out at a temperature near room temperature to avoid unwanted side reactions. In the following examples, all temperatures are uncorrected and the percentages are all by weight unless otherwise indicated.

12 151027

Preparation of Starting Materials (I) Preparation of 2- (2 ', 2', 21-trichloroethoxycarbonylamino) -thiazol-4-ylacetic acid.

(1) In 250 ml of acetone, dissolve 25.2 g of potassium thiocyanate and while the solution is cooled at -20 ° C, 50 g of 2,2,2-trichloroethyl chloroformate are added dropwise. After the dropwise addition is complete, the mixture is stirred at this temperature for 30 minutes. The precipitated potassium chloride is filtered off. To the filtrate is added 26 g of 17% methanolic ammonia at -10 ° C. The mixture is stirred for 45 minutes, after which the solvent is distilled off. The syrupy residue is recrystallized from aqueous methanol to give 21.8 g of N- (2,2,2-trichloroethoxycarbonyl) thiourea as colorless prisms melting at 189-190 ° C.

Elemental Analysis for C

Calculated: C 19.10, H 2.00, N 11.14

Found: C 19.22, H 1.96, N 11.50.

(2) In 3 ml of ethanol, dissolve 500 mg of N- (2,2,2-trichloroethoxy-carbonyl) thiourea, 416 mg of ethyl a) bromoacetoacetate and 3636 mg of Ν, Ν-dimethylaniline, and stir the solution at room temperature for 24 hours. After the solvent is distilled off under reduced pressure, the residue is dissolved in chloroform and washed once with 10% hydrochloric acid and then three times with a saturated aqueous solution of sodium chloride. After drying over magnesium sulfate, the chloroform layer is concentrated and the oily residue is passed through a column of silica gel and eluted with a 1: 1 mixture of benzene and chloroform. The above isolation purification procedure gives 540 mg of ethyl 2- (2 ', 2', 2'-trichloroethoxycarbonylamino) -thiazol-4-yl acetate, 30 m.p. 91-92 ° C.

Elemental analysis for C- ^ qH ^ CI ^^ O ^ S;

Calculated: C 33.21, H 3.07, N 7.75

Found: C 33.38, H 2.85, N 7.73 13 (3) In 3 ml of acetone, dissolve 500 mg of N- (2,2,2-trichloroethoxy-carbonyl) thiourea, 328 mg of ethyl m chloroacetoacetate and 237 mg of pyridine, and the solution is stirred at room temperature for 24 hours. Then, a similar treatment as in Example 2 gives 502 mg of ethyl 2- (2 ', 2', 2'-trichloroethoxycarbonylamino) -thiazol-4-yl acetate. This product is identical to the compound prepared by the procedure described above under (2).

(4) In 100 ml of dichloromethane, dissolve 18.6 g of ethyl 2-aminothiazol-4-yl acetate and 11.1 g of triethylamine, and while cooling the solution with ice, add 23.3 g of 2.2 , 2-trichloro-ethyl chloroformate. After the dropwise addition is complete, the mixture is stirred for 1 hour, then 50 ml of water is added to the reaction mixture.

The organic layer is separated, washed twice with 10% hydrochloric acid and once with water, then once with 10% aqueous sodium hydrogen carbonate solution and twice with saturated aqueous sodium chloride solution. Then, over magnesium sulfate, the magnesium sulfate is filtered off and the dichloromethane 20 is removed by distillation. To the resulting oily residue is added 80 ml of ethanol and the precipitate is filtered off (unreacted ethyl 2-aminothiazol-4-yl acetate: 9.7 g). The filtrate is concentrated and passed through a column of silica gel and eluted with a 1: 1 mixture of chloroform and benzene. The above isolation purification procedure gives 12.2 g of ethyl 2- (2 ', 2 1,21-trichloroethoxycarbonylamino) -thiazol-4-yl acetate.

This product is identical to the compound prepared above according to (2).

(5) In a mixture of 50 ml of water and 50 ml of methanol, dissolve 5.9 g of ethyl 1-2- (2,221-trichloroethoxycarbonylamino) -thiazol-4-yl acetate and 1.3 g of sodium hydroxide, and the solution is stirred at room temperature for 4 hours. Most of the methanol aides are added under reduced pressure, and the residue is washed with ethyl acetate (20 ml), acidified with 10% hydrochloric acid and extracted twice with 50 ml portions of ether. The ether extract is washed with water, dried and concentrated. The procedure gives 3.1 g of 2- (21,21,2'-trichloroethoxycarbonylamino) -thiazol-4-5 yl acetic acid, m.p. 164 to 164.5 ° C.

Elemental analysis for CgH ^Clg ^O₂S:

Calculated: C 28.81, H 2.12, N 8.40

Found: C 28.92, H 2.20, N 8.44.

(II) Preparation of 2- (β, β, β-trichloroethoxycarbonylamino) -10 thiazol-4-yl acetyl chloride hydrochloride.

In 20 ml of dichloromethane, 6.67 g of 2- (β, β, β-trichloro-ethoxycarbonylamino) -thiazol-4-yl-acetic acid are suspended, and while the suspension is stirred under ice-cooling, 4.15 g of finely crushed phosphorus pentachloride is added. the suspended 15 acid dissolves completely. After a period of approx. 5 minutes, fresh crystalline substance is excreted. The mixture is stirred at room temperature for 1 hour, after which the precipitate is filtered off and washed with petroleum ether. The procedure gives 6.59 g (yield 84.8%) of 2- (β, β, β-trichloroethoxycarbonylamino) -thiazol-4-yl-acetyl chloride hydrochloride, m.p. 109.7 ° C (decomposition).

Elemental Analysis for C

Calculated: C, 24.73; H, 1.81; N, 7.21

Found: C 24.40, H 1.63, N 6.94.

The process according to the invention is further illustrated in the following examples.

Example 1.

(1) In 10 ml of dichloromethane, dissolve 1,638 g of benzhydryl-7α-methoxy-7β-aminocephalosporanate and, while the solution is cooled with ice, add 1.5 ml of pyridine and immediately thereafter 2.70 g of 2- (β, β, β- trichloroethoxycarbonylamino) - thiazol-4-yl-acetyl chloride hydrochloride. The mixture is stirred for 15 minutes. It is stirred at room temperature for 20 minutes, then poured into ice water and extracted with ethyl acetate. The ethyl acetate layer is washed with 0.5 N hydrochloric acid, water, a 5% aqueous sodium bicarbonate solution and a saturated aqueous sodium chloride solution in the order in which it is dried over magnesium sulfate. The ethyl acetate is then distilled off to give an oily residue. The oil is purified by chromatography on silica gel. The procedure gives 1.096 g (yield 39.9%) of benzhydryl-7α-methoxy-7β- [2- (β, β, β-trichloroethoxycarbonylamino) -thiazol-4-yl-acetamido] -cepha-losporanate.

The infrared absorption spectrum (KBr) of this product shows an absorption of β-lactam at 1770 cm. The nuclear magnetic resonance spectrum (60 Mc, in deuteriochloroform) of the product shows a singlet attributable to the 3-acetyl group at 1.98 ppm. , a singlet as a result of 2-methylene protons at 3.33 ppm, a singlet as a result of 7a-methoxy at 3.34 ppm, a singlet attributable to the methylene protons in the thiazolylacetic acid moiety, at 3.74 ppm, a singlet as a result of the methylene protons in trichloroethoxycarbonyl at 20 4.84 ppm, a quartet due to 3-methylene protons at 4.90 ppm, a singlet for the 6-hydrogen at 5.05 ppm, a singlet attributable to the 5-hydrogen in the thiazole ring, at 6 , 57 ppm, a singlet attributable to the methine protons in benzhydryl at 6.85 ppm and a singlet due to the phenyl-25 protons in benzhydryl at 7.30 ppm.

(2) In 25 ml of 90% formic acid, 990 mg of benzhydryl-7α-methoxy-73- [2- (β, β, β-trichloroethoxycarbonylamino) -thiazol-4-yl-acetamido] -cephalosporanate is dissolved, and after addition of 860 mg of zinc dust while cooling with ice, the mixture is stirred for 1 hour.

The reaction mixture is poured into a saturated aqueous solution of sodium chloride and extracted with ethyl acetate. The ethyl acetate layer is washed with water, a 5% aqueous sodium hydrogen carbonate solution, and a saturated aqueous sodium chloride solution in the above order, then dried over magnesium sulfate.

The ethyl acetate is then distilled off to give 4.72 mg (yield 61.5%) of benzhydryl-7α-methoxy-73- (2-aminothiazol-4-yl-acetamido) -cephalosporanate. The infrared absorption spectrum of this product shows an absorption of β-lactam at 1770 cm @ 5. The nuclear magnetic resonance spectrum (60 Mc, in deuterio-chloroform) of this ester shows a singlet attributable to the 3-acetyl group at 2.00 ppm. a quartet as a result of 2-methylene protons at 3.36 ppm, a singlet as a result of 7-methoxy at 3.45 ppm, a singlet attributable to the 10 methylene protons in thiazolylacetic acid, at 3.56 ppm, a quartet which must is attributed to 2-methylene protons, at 4.90 ppm, a singlet due to 6-hydrogen at 5.08 ppm, a singlet attributable to the 5-hydrogen in the thiazole ring, at 6.28 ppm, a singlet due to the methine protons in benzhydryl at 15.93 ppm and a singlet due to the phenyl core protons in benzhydryl at 7.30 ppm.

(3) While cooling with ice and stirring, 335 mg of benzhydryl-7α-methoxy-7β- (2-aminothiazol-4-yl-acetamido) cephalosporanate are added to a mixture of 1.5 ml of trifluoroacetic acid and 1.5 ml of anisole, 20 and the mixture is stirred for 30 minutes. The reaction mixture is poured into 50 ml of anhydrous ether and the resulting white precipitate is isolated and washed with ether. The procedure gives crude 7α-methoxy-7β- (2-aminothiazol-4-yl-acetamido) -cephalosporanic acid trifluoroacetate (185 mg). This product is dissolved in a 25% aqueous solution of sodium bicarbonate and the solution is passed to a column of "Amberlite XAD-2" ® and eluted with water. This purification procedure gives 131 mg (50.8%) of sodium tri-7α-methoxy-73- (2-aminothiazol-4-yl-acetamido) cephalo-sporanate trihydrate.

Elemental analysis for C- gHH ^^O ^N ^S₂Na.3H₂O:

Calculated: C 37.06, H 4.47, N 10.80

Found: C 37.36, H 4.14, N 10.50.

17 151027

The nuclear magnetic resonance spectrum (100 Me, in D2O) of this product shows a singlet due to 3-acetyl at 2.26 ppm, a quartet attributable to 2-methylene protons, at 3.52 ppm, a singlet attributable to 7-methoxy, 5 at 3.70 ppm, a singlet attributable to the methylene protons in the thiazolylacetic acid function, at 3.80 ppm, a quartet as a result of 3-methylene protons at 4.95 ppm, a singlet due to 6- hydrogen at 5.32 ppm and a singlet attributable to 5-hydrogen in the thiazole ring at 6.70 ppm.

Example 2.

(1) In 4 ml of water containing 208 mg of sodium hydrogen carbonate are dissolved 431 mg of 7α-methoxy-73- (2-aminothiazol-4-yl-acetamido) -cephalosporanoic acid trifluoroacetate, 108 mg of 1-methyl-1H -tetrazole-5-thiol and 24.6 mg of triethylbenzylammonium bromide, 15 and the reaction mixture is stirred at 60 ° C for 6 hours in an atmosphere of nitrogen gas. After cooling, the reaction mixture is passed through a column of "Amberlite XAD-2" ® and eluted with water.

The above purification procedure gives 158 mg (36.8%) of sodium 7a-methoxy-73- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-20H-tetrazol-5-yl-thiomethyl) 3-cephem-4-carboxylate.

Elemental Analysis for C ^ gHHO ^NgSNa.H ^O:

Calculated: C 35.68, H 3.55, N 20.86

Found: C 35.56, H 3.36, N 19.83.

The infrared absorption spectrum (KBr) of this product 25 shows an absorption of β-lactam at 1750 cm. The nuclear magnetic resonance spectrum (100 Me, in D 2 O) for the same product shows a quartet attributable to 2-methylene protons at 3.60 ppm, a singlet as a result of 7a-methoxy at 3.65 ppm, a singlet as a result of the methylene protons in the 30 thiazolylacetic acid function at 3.77 ppm, a singlet attributable to tetrazole methyl protons, at 4.17 ppm, a quartet attributable to 3-methylene protons, at 4.30 ppm, a singlet attributable to 6- hydrogen, at 5.24 ppm, and a singlet due to the 5-hydrogen in the thiazole ring at 6.67 ppm.

(2) The same procedure as (1) in the absence of triethylbenzylammonium bromide also gives sodium 7a-methoxy-73- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazole) 5-yl-thiomethyl) -3-cephem-4-carboxylate salt. This product is identical to the compound obtained in (1).

Example 3

Dissolve 2.62 g of benzhydryl-7α-methoxy-78-amino-3- (1-methyl-1H-tetrazol-5-yl-thiomethyl) -3-cephem-4-carboxylate in 20 ml of dichloromethane, and cool with ice Add 3.0 ml of pyridine and then 3.88 g of 2- ((3, ft, 3-trichloroethoxycarbonylamino) -thiazol-4-yl-acetylchloride hydrochloride. The mixture is stirred for 15 minutes and then at room temperature for 20 minutes. minutes.

Then, the reaction mixture is poured into ice water and extracted with ethyl acetate. The ethyl acetate layer is washed with 0.5 N hydrochloric acid, 15 water, and a saturated aqueous sodium chloride solution in the above order, then dried over magnesium sulfate. The ethyl acetate is distilled off to give an oily residue.

This oil is purified by chromatography on silica gel. The procedure gives 1.82 g (43%) of benzhydryl-7α-methoxy-73- [2-0,3,8-trichloroethoxycarbonylamino) -thiazol-4-yl-acetamido] -3- (1-methyl-1H) tetrazole-5-yl-thiomethyl) -3-cephem-4-carboxylate. A 1.50 g portion of this ester is dissolved in 40 ml of 90% formic acid and, with cooling with ice and stirring, 1.30 g of zinc dust is added. The reaction mixture is stirred for 1 hour. The reaction product is poured into a saturated aqueous solution of sodium chloride and extracted with ethyl acetate. The ethyl acetate layer is washed with water and a saturated aqueous sodium chloride solution and dried over magnesium sulfate. The ethyl acetate is distilled off to give 753 mg (63.4%) of crude benzhydryl-7α-methoxy-78- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazol-5-yl) thiomethyl) -3-cephem-4-carboxylate.

A 700 mg portion of this product is added to a mixture of 3.0 ml of trifluoroacetic acid and 3.0 ml of anisole, and the reaction is carried out under cooling with ice and stirring. The reaction mixture is poured into 100 ml of anhydrous ether and the resulting precipitate is isolated by suction and washed with ether. The procedure gives 373 mg of 7α-methoxy-73- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazol-5-yl-thiomethyl) -3-cephem-4-carboxylic acid trifluoroacetate. This product is dissolved in a 5% aqueous solution of sodium bicarbonate and passed through a column of "Amberlite XAD-2" ®, then eluted with water. The above purification procedure gives 303 mg of sodium 7α-methoxy-73- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-ΙΟH-tetrazol-5-yl-thiomethyl) -3-cephem-4 carboxylate.

This product is completely identical to the product obtained in Example 2.

Example 4

Dissolve 953 mg of benzhydryl-7a-methoxy-7β- (D-5-trichloroethoxycarbonylamino-5-benzhydryloxycarbonylvalerylamido) cephalosporanate in 20 ml of dichloromethane, to which 740.8 mg of N-trimethylsilyl-trifluoroacetamide is added. - (3,3,3-tri-chlorethoxycarbonylamino) -thiazol-4-yl-acetyl chloride hydro-chloride. The mixture is heated at 41 ° C with stirring for 24 hours. After cooling, the reaction mixture is filtered to remove the insoluble material and the filtrate is concentrated under reduced pressure. The residue which is crude benzhydryl-7a-methoxy-73 "[((D-5-trichloroethoxycarbonylamino-5-benzhydryl-oxycarboxyvaleryl) - (2-3,3,3-trichloroethoxycarbonylaminothiazol-4-yl-acetyl) -amino] - cephalosporanate, dissolved in 10 ml of 90% formic acid. After adding 4 g of zinc dust, the solution is stirred at room temperature for 5 hours and then filtered. To the filtrate is added 5 ml of a saturated sodium chloride solution and extracted with ethyl acetate. The ethyl acetate layer is washed with water and dried over magnesium sulfate. The ethyl acetate is then juxtaposed and the oily residue is purified by chromatography on silica gel. The procedure gives 197 mg (32.4%) of benzhydryl-7α-methoxy-78 78 (2-aminothiazol-4-yl-acetamido) cephalosporanate. This product is identical to the product obtained in Example 1 (2).

20 151027

Example 5

To 50 ml of dichloromethane is added 4.68 g of benzhydryl-7a-methoxy-78-aminocephalosporanate and while cooling the mixture at -40 ° C, 2.4 g of Ν, Ν-dimethylaniline is added. With vigorous stirring, 2.91 g of 4-bromo-3-oxobutyryl bromide is added dropwise over a period of approx. 10 minutes, during which time the temperature of the reaction mixture rises from -40 to -15 ° C. Then stirring is continued at -15 to -10 ° C for 30 minutes. The reaction mixture is washed with water, dilute hydrochloric acid, water and saturated aqueous sodium chloride solution and dried. The solvent is distilled off and an oily residue is obtained. This product, ie crude benzhydryl-7α-methoxy-73- (4-bromo-3-oxo-butyrylamido) cephalosporanate is dissolved in 50 ml of methanol and, after addition of 0.91 g of thiourea, the reaction is carried out at room temperature with stirring for 2 hours. . The methanol is distilled off under reduced pressure and the residue is washed with ethyl acetate and dissolved by adding 30 ml of water. Then, a 5% aqueous solution of sodium hydrogen carbonate is added and the separated substance is extracted with 20 ethyl acetate. The ethyl acetate layer is washed with saturated sodium chloride solution and dried. The ethyl acetate is distilled off and 2.43 g of an oily residue are obtained. This product is identical to benzhydryl-7a-methoxy-73- (2-aminothiazol-4-yl-acetamido) cephalosporanate obtained in Example 1 (2).

Example 6

To 30 ml of dimethylacetamide is added 5.24 g of benzhydryl-7oc-methoxy-73-amino-3- (1-methyl-1H-tetrazol-5-yl-thiomethyl) -3-cephem-4-carboxylate and, under cooling, 2.91 g of 4-bromo-3-oxobutyryl bromide are added over a period of about 40 ° C. 10 30 minutes. During this time, the temperature of the reaction mixture rises from -40 to -15 ° C. The mixture is further stirred between -15 and -10 ° C for 1 hour, then poured into 100 ml of ice water. The mixture is adjusted to pH 8.0-8.5 with sodium hydrogen carbonate and extracted with ethyl acetate. The ethyl acetate layer 35 is washed with water, dilute hydrochloric acid and a saturated aqueous sodium chloride solution in the order in which it is dried. The ethyl acetate is distilled off under reduced pressure and an oily residue is obtained. This product, ie benzhydryl-7α-methoxy-7β- (4-bromo-3-oxobutyrylamido) -3- (1-methyl-5H-tetrazol-5-yl-thiomethyl) -3-cephem-4-carboxylate, dissolved in 50 ml of methanol, and after the addition of 0.91 g of thiourea, the mixture is stirred at room temperature for 2 hours. The methanol is distilled off under reduced pressure and the residue is washed with ethyl acetate and dissolved in 30 ml of water. Then a 5% aqueous solution of sodium hydrogen carbonate is added and the separated substance is extracted with ethyl acetate. The ethyl acetate layer is washed with water and saturated aqueous sodium chloride solution and dried. The ethyl acetate is distilled off under reduced pressure to give crude benzhydryl-7α-methoxy-7β - (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazol-5-yl-thiomethyl) -3 -cephem-4-carboxylate. While cooling with ice and stirring, this product is added to a mixture of 35 ml of trifluoroacetic acid and 35 ml of anisole and the reaction is allowed to proceed for 30 minutes. Then 700 ml of water-free ether is added and the precipitate is isolated by suction and washed with ether. The procedure gives crude 7α-methoxy-73- (2-amino-thiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazol-5-yl-thio-methyl) -3-cephem-4-carboxylic acid trifluoroacetate. This product is dissolved in a 3% aqueous solution of sodium hydrogen carbonate and the solution is passed through a column of "Amber-lite XAD-2" ® and eluted with water. The procedure gives 1.25 g of sodium 7a-methoxy-73- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazol-5-yl-thiomethyl) -3-cephem-4 carbox-ylate. This product is identical to the product obtained in Example 2 (1).

Claims (2)

151027 An analogous process for the preparation of 7α-methoxy-7β- (2-aminothiazol-4-ylacetamido) cephalosporins of the general formula NH0 Ss OCH-, Y); p N1_L1-CH2CONH-jj / V o ^ JR (I> COOH wherein R is acetoxymethyl or 1-methyl-1H-tetrazol-5-ylthiomethyl, or pharmaceutically acceptable salts or C1-2a1 coxymethyl 1-, aC · alkoxyethyl 1 -, 3-alkylthiomethyl, C2_5acyloxymethyl or a-C2_cjacyloxy-C2_4 alkyl esters thereof, characterized by a) reacting a 7a-methoxycephalosporin derivative of the formula? CH3 is \ H2N -__ ^ N (II) COOR5 wherein R is as defined above and R 1 is a hydrogen atom or an ester group, or a salt thereof with an aminothiazolyl acetic acid derivative of the formula γ -CH 2 COOH (III) wherein R 1 is a protected amino group, or a reactive derivative thereof, removing the ester group and protecting group if necessary, or b) reacting a 7α-ethoxycephalosporin compound of formula 151027 and 3; s HalCH2COCH2CONH —- ^ \ 0Λ-Νγ! -κ <ιν> COOR5 wherein Hal is a halogen and R and R have the same meanings as above, or a salt thereof with thiourea, where necessary removing the ester group, or 5 c ) reacting a 7α-methoxycephalosporin derivative of the formula V? cH3 II I; s N-1-CH 2 CONH-j- / \ o0'CH 2 X (VI> COOH 4 wherein R is an amino group which may be optionally protected and X is an acetoxy or carbamoyloxy group, or a salt thereof with 1-methyl-1H -tetrazole-5-thiol, where necessary removing the protecting group, or d) reacting a 7α-methoxycephalosporin compound of formula and 3 HOOC; s \ e (ch2) 3conh- |. COOCH2CCl3 T COOR5 wherein R and R5 have the same meanings as above, or a salt thereof having a reactive derivative of an aminothiazolyl-acetic acid derivative of the formula Rv \ tJ I _oti nnr \ u ίτττΜ 151027 wherein R1 has the same meaning as above, in the presence of a silylating agent to remove the protected aminoadipoyl group and, if necessary, the ester group and protecting group and, if desired, converting a obtained compound of formula (I) into a pharmaceutically acceptable salt or a pharmaceutically acceptable ester thereof. Process according to claim 1, characterized in that 7a-methoxy-73- (2-aminothiazol-4-yl-acetamido) -3- (1-methyl-1H-tetrazol-5-yl-thiomethyl) - 3-cephem-4-carboxylic acid or a pharmaceutically acceptable salt or ester thereof.