KR930007263B1 - Process for preparing ceph 3-em-4-carboxylic acid derivatives - Google Patents

Abstract

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Description

Method for preparing ceph-3-m-4-carboxylic acid derivative

The present invention relates to a process for the preparation of the novel ceph-3-m-4-carboxylic acid derivatives.

According to the invention, a novel 7- (3-chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl)- Thiomethyl-sef-3-em-4-carboxylic acid and pharmaceutically acceptable salts thereof are provided.

Also according to the invention,

a) 3-chloro-isoxazole-acetic acid of the following general formula (II) or a reactive derivative thereof is 7-amino-3- (1-methyl-1H-1,2,3,4- of general formula (III) React with tetrazol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid and from the reaction mixture obtained 7- (3-chloro-isoxazol-5-yl of formula (I) Acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3-em-4-carboxylic acid, if necessary, Convert it to a pharmaceutically acceptable salt thereof, and separate the salt from the reaction mixture,

b) 1-methyl-1H-1,2,3,4-tetrazol-5-yl thiol of formula (IV) is prepared as 7- (3-chloroisoxazol-5-yl) acetamido-cephalo 7- (3-chloroisoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazole of the following general formula (I) obtained by reacting with -5 -yl) thiomethyl-sef-3-m-4-carboxylic acid, which is then converted to its pharmaceutically acceptable salt, thereby separating the salt from the reaction mixture, 7 -(3-Chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3-m- Methods of preparing 4-carboxylic acids and pharmaceutically acceptable salts thereof are provided.

3-chloro-isoxazoleacetic acid of the general formula (II) or a reactive derivative thereof according to the method a) of the present invention is converted to 7-amino-3- (1-methyl-1H-1,2,3 React with, 4-tetrazol-5-yl) thiomethyl-sef-m-4-carboxylic acid. This reaction can be carried out in a solvent, preferably an aqueous acetone medium or a water immiscible organic solvent. This reaction is carried out under stirring and the reaction time is generally 30 minutes to 3 hours.

According to process b) of the present invention, 1-methyl-1H-1,2,3,4-tetrazol-5-yl-thiol of general formula (IV) is converted to 7- (3-chloro-isoxazole-5- (I) react with acetamido-cephalosporonic acid. This reaction is carried out in a solvent, preferably in a mixture of water and acetone, at 30 to 90 ° C., preferably at 60 to 65 ° C. and at pH 4.5 to 6.0. The reaction time is generally 2 to 10 hours.

In the field of semisynthetic β-lactam derivatives, many experiments have been carried out to prepare compounds having a broad and specific antimicrobial spectrum. An important group of such compounds includes substituted or unsubstituted isoxazole groups each bonded via an acetamido group to the six carbon atom of 6-amino-phenicylanic acid and the seven carbon atom of 7-aminocephalosporanic acid. Representatives of these groups of compounds show significant antimicrobial effects.

Effective molecules with isoxazol-4-yl-acetamido groups substituted at the 6-position of the penicillin molecular sieve are known as medicaments. Molecules of this type are described in US Pat. Nos. 2,996,501, 3,239,507 and French Patent BSM 6432.

U.S. Patent No. 4,394,504 describes penicillin and cephalosporin derivatives having an alkoxyamino group at the α-position linked to the isoxazole ring in addition to a 3-amino-isoxazol-5-yl acetamido group. This compound described in the above-mentioned United States patent shows important activity against Staphylococcus strains.

German Patent Publication No. 2,155,081 describes penicillin and cephalosporin derivatives containing a (3-substituted phenyl) isoxazol-5-yl acetamido group. However, it has not been actually described or tested that phenylisoxazole derivatives exhibit significant antimicrobial effects on the microorganisms used.

Furthermore, German Patent Publication No. 2,409,949 describes isoxazol-5-yl acetamido derivatives. However, the isoxazole ring of the derivative has other substituents instead of phenyl substituents.

The chemotherapy and pharmaceutical effects of some compounds described in this German patent have been determined. However, the tested molecules do not exhibit significant antimicrobial activity against the test microorganisms used.

MIC values of these compounds are also described. However, the value does not reach the activity required for the active ingredient which improves a drug.

It is an object of the present invention to provide a process for the preparation of novel ceph-3-m-4-carboxylic acids having significant pharmaceutical properties.

Surprisingly, new 7- (3-chloro-isoxazol-5-yl) -acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5- of formula (I) It was found that yl) thiomethyl-sef-3-m-4-carboxylic acid and its pharmaceutically acceptable salts show a very high and useful antibacterial effect. This was demonstrated by chemotherapy screens and pharmaceutical tests. Novel 7- (3-Chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3 Although -M-4-carboxylic acid is included in the general formula of German Patent No. 2,409,949, its preparation is not described in the German patent and its physicochemical data and characteristic constants and MIC values are not described.

7- (3-chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3-m The antimicrobial activity of the 4-carboxylic acid is evidenced by the MIC value of this compound. This compound is tested against several test microorganisms, using commercially available reference compounds as medicaments. The results are summarized in Table 1.

TABLE 1

Absorption testing has surprisingly found that compounds of formula (I) belonging to the second generation of cephalosporin derivatives in MIC values can be used to prepare pharmaceutical compositions suitable for oral administration as opposed to other antibiotics of this group. appear. The results are shown in Table II.

TABLE 2

Compounds of the general formula (I) with β-lactamge are not toxic in acute toxicity studies administered in a single acute dose. Mice are not lethal even when intraperitoneally or orally administered 2500 mg / kg body weight.

LD ₅₀ = 2500 mg / kg body weight

In addition, a pharmacokinetic test is performed to determine the absorption of the compound of formula (I). This test is determined by intraperitoneal or oral administration to CFLP mice. Twenty mice are treated simultaneously with an aqueous solution of the compound of formula (I) at an appropriate concentration.

Dosage: Intraperitoneal: 0.1ml from solution with 4mg / ml concentration for 20mg / kg body weight

Oral: For 80 mg / kg body weight, 0.4 ml from solution with 4 mg / ml concentration.

The average body weight of the mice is 20 g. At some point, the mice are lethal and collected (heparin is added to prevent blood clotting).

The active ingredient content in the blood is determined microbiologically (test microorganism: Bacillus subtilis ATCC 6633). The results are summarized in Table 3.

a / intraperitoneal administration (20mg / kg body weight)

TABLE 3

b / oral administration (80 mg / kg body weight)

Absorption of the compound of formula (I) is also tested in Beagle dogs. Test compounds are administered orally and intramuscularly (20 mg / kg body weight for intramuscular administration, 80 mg / kg body weight for oral administration). Bacillus subtilis ATCC 6633 is used as the test microorganism. Cut the vein and draw a blood sample. The results are shown in Table IV.

a / intramuscular administration (20mg / kg body weight)

TABLE 4

b / oral administration (80 mg / kg body weight)

The concentration curve formed in the blood upon oral administration indicates that it is suitable for preparing a pharmaceutical composition for oral administration of a compound of formula (I).

The binding of the serum protein example of the compound of formula (I) is determined. Two methods are used. One of these methods is based on equilibrium dialysis (Scholten: Antibiot. Chemother. No. 12. page 103 (1964)) and the other is the so-called "large plate" method (F. Kawanagh: Analytical Microbiol. Acad Press) NY (1963).

The ratio of the compound of general formula I to serum protein is 50 to 70%. This value also indicates the suitability of oral administration.

In vivo activity of compounds of formula (I) is determined in CFLP-based mice. To determine the ED ₅₀ value, mice are intraperitoneally infected with 10 × LD ₁₀₀ of a 6-8 hour culture of microorganisms. One hour after infection, mice are treated with an aqueous solution of the test compound. Use commercially available agents as reference compounds. The results are evaluated by the Lichfield-Wilcockson method. According to the data characteristic of the conventional β-lactam system, as a result of treatment with a compound of general formula (I), the number of living animals remained unchanged at 48 hours after treatment for Staphylococcus or Proteus infection. have.

In order to show that the compound of general formula (I) is more active than the compound of German Patent No. 2,409,949, the following test is carried out by the same method as described above.

Comparison of ED50 Values (mg / kg)

Test animals: CFLP mice, females and males with an average weight of 20 g

Bacteria Used for Infection: See Table

Infection method: Intramuscular administration by dissolving in 2.5% mucin

TABLE 5

Sodium 7-[(3-chloroisoxazol-5-yl) acetamido] cephalosporate

** Sodium 7-[(3-chloroisoxazol-5-yl) acetamido] -3-[(5-methyl-1,3,4-thiadiazol-2-yl) thiomethyl] -sef- 3-m-4-carboxylate

According to another aspect of the present invention, as active ingredient, the substance 7- (3-chloro-isoxazol-5-yl) acetamido-5- (1-methyl-1H-1,2,3,4-tetra A sol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid or a pharmaceutically acceptable salt thereof is provided to provide a pharmaceutical composition comprising a suitable inert solid or liquid pharmaceutical carrier.

The pharmaceutical composition may be prepared by a method known in the pharmaceutical industry.

The invention is further illustrated by the following examples, which do not limit the invention.

Example 1

7- (3-chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3-m Preparation of 4-carboxylic acid and its sodium salt

4.99 g (30.9 mmol) of 3-chloro-isoxazol-5-yl acetic acid and 7.07 g (33.99 mmol) of phosphorus pentachloride are dissolved in 120 ml of anhydrous benzene with constant stirring. The reaction mixture is left overnight at rt and 1 h at 60 ° C. Benzene is distilled off and the residue is treated with anhydrous petroleum ether several times, followed by evaporation until the petroleum ether is gone. The residue was dissolved in 40 ml of anhydrous acetone and the resulting solution was stirred at 0-5 ° C. for 50 minutes at 6.75 g (20.6 mmol) of 7-amino-3- (1-methyl-1H-1,2, To a solution of 3,4-tetrazol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid, 5.2 g (61.9 mmol) sodium bicarbonate, 144 ml water and 103 ml acetone. After the addition was complete, the reaction mixture was stirred for 1 h at 0-5 ° C. and 2 h at room temperature, adjusting the pH to 7-8 by adding saturated sodium bicarbonate solution. Dilute sulfuric acid is added to the mixture, acidified to pH 1.5-2, and extracted three times with 100 ml of ethyl acetate each. The ethyl acetate extract is dried over magnesium sulfate and the solvent is removed.

The evaporation residue was treated with diethyl ether, filtered, washed and dried to give 3.5 g of 7- (3-chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2, 3,4-tetrazol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid is obtained.

The compound is dissolved in anhydrous acetone and an equivalent amount of anhydrous sodium acetate solution dissolved in 10% methanol is added. The solution is stirred at 20 ° C. for 1 hour and diluted with the same volume of diethyl ether. 7- (3-chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3-m Sodium salt of 4-carboxylic acid is precipitated.

Characteristic data:

¹ H NMR: (DMSO-d ₆ ): 3.52 (ABq, 2H, H-2), 3.90 (s, 3H, N-CH ₃ ), 3.97 (s, 2H, CH ₂ CO), 4.35 (ABq, 2H , H-10), 4.97 (d, 1H, H-6), 5.52 (q, 1H, H-7), 6.67 (s, 1H, H-Ar), 9.25 (d, 1H, C ⁷ -NH) .

Melting Point: 150 ~ 155 ℃ (Decomposition)

Example 2

7- (3-Chloro-isoxazol-5-yl) acetamido-5- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sep-3-m Preparation of 4-carboxylic acid and its sodium salt

10.68 g (0.04 mole) of pentachlorophenol and 8.32 g (0.04 mole) of thiochlorohexylcarbodiimide are dissolved in 230 ml of anhydrous dichloromethane and 6.4 g (0.04 mole) of 3-chloro-isoxazole-5- Monoacetic acid is added. The reaction mixture is stirred at room temperature for one day, and the precipitated dicyclohexylcarbodiimide is filtered off. 13.2 g (0.04 mol) of 7-amino-3- (1-methyl-1H-1,2,3,4-) of pentachlorophenyl ester dissolved in dichloromethane thus obtained was constantly stirred at 0 ° C. Tetrazol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid, 16.8 g (0.12 mole) triethylamine and 120 ml dichloromethane solution are added. After complete addition, the reaction mixture is warmed to room temperature and stirred at this temperature for 1 hour. After completion of the reaction, dichloromethane is distilled off in vacuo, the residue is dissolved in aqueous ethyl acetate, acidified to pH 2 with 2N sulfuric acid, the phases are separated and the organic layer is dried over magnesium sulfate and evaporated. The residue is washed with diethyl ether, filtered and washed and dried in vacuo with phosphorus pentoxide at room temperature. The product obtained is converted to sodium salt as in Example 1 to give 12 g of sodium salt. Yield 61% (yield 63.8% free acid).

Example 3

7- (3-Chloro-isoxazol-5-yl) acetamido-5- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sep-3-m Preparation of 4-carboxylic acid and its sodium salt

Dissolve 0.084 g (1 mmol) of sodium bicarbonate and 0.415 g (1 mmol) of 7- (3-chloro-isoxazol-5-yl) acetamidocephalosporanic acid in a mixture of 17 ml of water and 6 ml of acetone. Let's do it. 0.14 g (1.2 mmol) of 1-methyl-1H-1,2,3,4-tetrazol-5-yl thiol was added to the solution, and the reaction mixture was adjusted to pH 5.0-5.5 with saturated sodium bicarbonate solution. While standing for 8 hours at 60 ~ 65 ℃.

After completion of the reaction, the pH of the reaction mixture is adjusted to pH 2 with 3N hydrochloric acid. The mixture is extracted with ethyl acetate, the organic phase is evaporated and the residue is washed with ether to give 0.35 g of the desired free acid. Yield 74.5%.

The free acid thus obtained is converted to the sodium salt according to the method of Example 1.

Claims (3)

3-Chloro-isoxazole-acetic acid or a reactive derivative thereof of the general formula (II) may be substituted with 7-amino-3- (1-methyl-1H-1,2,3,4-tetrazole) 7- (3-chloro-isoxazol-5-yl) acetamido-3 of the following general formula (I), reacted with -5-yl) thiomethyl-sef-3-m-4-carboxylic acid -(1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid separated from the reaction mixture 7- (3-Chloro-isoxazol-5-yl) acetamido-3- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl- of formula (I) Cef-3-em-4-carboxylic acid and a method for preparing a pharmaceutically acceptable salt thereof.

The process according to claim 1, wherein the chloride or pentachlorophenyl ester thereof is used as the reactive derivative of 3-chloro-isoxazole-acetic acid of general formula (II). To 1-methyl-1H-1,2,3,4-tetrazol-5-yl thiol of formula (IV), 7- (3-chloro-isoxazol-5-yl) acetylamido-cephalospo Reaction with lanic acid and obtained 7- (3-chloro-isoxazol-5-yl) acetamido-5- (1-methyl-1H-1,2,3,4-tetra of formula (I) 7- (3-chloro-isoxazole-5- of formula (I), characterized in that sol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid is separated from the reaction mixture. Yl) acetamido-5- (1-methyl-1H-1,2,3,4-tetrazol-5-yl) thiomethyl-sef-3-m-4-carboxylic acid and pharmaceutically acceptable Method for preparing the salt thereof.