DK142913B - Analogous Process for Preparation of Cephalosporanoic Acid Derivatives. - Google Patents

Description

(11) PUBLICATION 142913 DENMARK (51) Int. Cl.3 c 07 D 501/36 (21) Application No. 2421/75 (22) Filed on 5 · May 1975 (24) Running day, 5 May 1975 (44) The application presented and the petition published on 25 · ίβΐ). 1 981

DIRECTORATE OF

PATENT AND TRADE MARKET <30> Pnontet edited from the

14 jun. 1972, 262905, US

15-s ep. 1972, 289499, US

(71) SMITH KLINE & FRENCH LABORATORIES, 1 500 Spring Garden Street, Phila = Helphia, Pennsylvania 19101, US.

(72) Inventor: George Lawrence Dunn, 690 Mallard Road, Wayne, Penneyl = vania, US: John Ruseel Eugene Hoover, 624 Crescent Avenue, Glenside, Pennsylvania, US.

(74) Plenipotentiary in the proceedings:

The company Chas. Hude._ (54) Analogous Process for Preparation of Cephalosporanoic Acid Derivatives.

The present invention relates to an analogous process for the preparation of antibacterial cephalosporanoic acid derivatives of the formula HO—-CHCOOH-t-S SN (j)

NH2 oJ-i ^^ J-CH2S-R

C00H

wherein R is 1,2,3-triazolyl optionally substituted with an alkyl group of 1-4 carbon atoms.

The process of the invention is characterized in that (1) an acetoxymethyl cephalosporin compound of formula 142913 2 1 / S ·.

Εωη-f I (ii) 0 = * - ^ Ns ^ ifl-CH2 COOCH3

COOH

livor R ^ is 110 - ('S-CHCO wherein the RH9 group is suitably protected, w / fe2 if necessary, or H is reacted with a heterocyclic thiol compound of formula HS-R (III) wherein R is as defined above, and (2) when R "is" H, the resultant compound is acylated with a p-hydroxyphenylacetic acid compound of the formula HO - ^ y - CHCOOH (IV) \ = z / rh2 or an acylating or activated derivative thereof wherein the N 1 group is suitably protected if necessary and (3) any protecting group is removed.

Among the preferred compounds obtained by the process of the invention are: 7- (p-hydroxy-α-aminophenylacetamido) -3- (1,2,3-triazol-4-ylthiomethyl) -3-cephem-4-carboxylic acid 7- (p-hydroxy-α-aminophenylacetamido -3- (4-methyl-1,2,3-triazol-5-ylthiomethyl) -3-cephem-4-carboxylic acid.

The antibacterial compounds obtained by the process of the invention unexpectedly have advantageous properties compared to related compounds. Eg. compound 7- (α-amino-β-hydroxyphenylacetamido) -3- (1,2,3-triazol-4-ylthiomethyl) -3-cephem-4-carboxylic acid (Compound 60771) is advantageous compared to Compound 7- (α-Aminophenylacetamido) -3- (1,2,3-triazol-4-ylthiomethyl) -3-cephem-4-carboxylic acid (Compound 60222) by providing higher maximum serum concentrations in mice and especially higher serum half-lives. As a result, the effect observed after both oral and subcutaneous administration to mice is noticeably improved, as shown by lower ED5Q. The data obtained are shown in Tables A and B.

Table A

Serum concentration in mice

Max. concentrate

Administration Half-life

Compound Dosage route (g) / ml) (min) 60771 20 mg / kg p.o. 52 62 60222 20 mg / kg p.o. 15 48 60771 20 mg / kg s.c. 54 71 6022a 20 mg / kg s.c. 55 54

Table B

Mouse protection studies

Compound Test Organism Route of Administration ED ^ (mg / kg) 60771 E. coli 12140 s.c. <0.8, 0.8 60222 E. coli 12140 s.c. <5, 5.6 60771 E. coli 12140 p.o. <0.8, 1.2 60222 E. coli 12140 p.o. <12.5, 4 60771 K. pneumoniae 4200 s.c. 0.6, 0.6 60222 K. pneumoniae 4200 s.c. 4.8 60771 E. pneumoniae 4200 p.o. 0.4, 0.5 60222 E. pneumoniae 4200 p.o. 12.5

Compound 60771 is also advantageous compared to 7- (α-amino-p-hydroxyphenylacetamido) -3- (5-methyl-1,2,4-triazol-3-ylthiomethyl) -3-cephem-4-carboxylic acid (compound 61529) by having noticeably lower ED, -q in the mouse protection test. Data obtained are shown in Table C.

142913 4

Table C

Mouse protection studies

Compound Test Organism Administration Pathway (ED / Q) 60771 E. coli 1214-0 s.c. <0.8, 0.8 61529 E, coli 12140 s.c. 10.7 60771 E. coli 12140 p.o. <0.8, 1.2 61529 E. coli 12140 p.o. 7.5 60771 K. pneumoniae 4200 s.c. 0.6, 0.6 61529 E. pneumoniae 4200 s.c. 8.6 60771 E. pneumoniae 4200 p.o. 0.4, 0.5 61529 E. pneumoniae 4200 p.o. 16

In addition, the compound 7- (α-amino-β-hydroxyphenylacetamido) -3- (4-methyl-1,2,3-triazol-5-ylthiomethyl) -3-cephem-4-carboxylic acid (61775) is advantageous compared to 7- (α-Aminophenylacetamido) - 3- (4-methyl-1,2,3-triazol-5-ylthiomethyl) -3-cephem-4-carboxylic acid (61348) by having lower ED ^q in mouse protection studies. The data is shown in Table D below.

Table E

Mouse protection studies

Compound Experimental Organism Administration Pathway (mg / kg) 61775 E. coli 12140 s.c. 1.8 61348 E. coli 12140 s.c. 42, 18.2 61775 E. coli 12140 p.o. 5.6, 3 61348 E. coli 12140 p.o. 50, 19 61775 E. pneumoniae 4200 s.c. 2.8 61348 E. pneumoniae 4200 s.c. 20 61775 E. pneumoniae 4200 p.o. 5.2 61348 E. pneumoniae 4200 p.o. 146

The compound 7- (α-amino-β-hydroxyphenylacetamido) -3- (1-methyl-1,2,3-triazol-5-ylthiomethyl) -3-cephem-4-carboxylic acid (60876) is also advantageous compared to 7- (α-Aminophenylacetamido) -3- (1-methyl-1,2,3-triazol-5-ylthiomethyl) -3-cephem-4-carboxylic acid (60637) by having lower ED maximum serum concentrations and half-lives, as shown in Tables E and F, respectively.

Table E

Mouse protection studies

Compound Test Organism Route of Administration ED ^ q (E'S / kg) 60876 E. coli 12140 s.c. 5.2 60637 E. coli 12140 s-c 21.5 60876 E. coli 12140 p.o. 6.2 60637 E. coli 12140 p.o. > 50 60876 E. pneumoniae 4200 s.c. 3.5 60637 K. pneumoniae 4200 s.c. 40 60876 K. pneumoniae 4200 p.o. 6 60637 K. pneumoniae 4200 p.o. > 200

Table F

Serum concentrations in mice

Max. concentrate

Administration Half-life

Compound Dosage route (µg / ml) (min) 60876 20 mg / kg p.o. 14 48 60637 20 mg / kg p.o. 1.8 * 60876 20 mg / kg s.c. 44 48 60637 20 mg / kg s.c. 21 12 * Too small to matter.

The acylation of the 7-amino group by the process of the invention is carried out with a p-hydroxyphenylglycine. Prior to acylation, it is desirable to protect the amino group of the glycine moiety with an easily removable protecting group such as t-butoxycarbonyl, benzyloxycarbonyl, trichloroethoxycarbonyl or the like protecting group commonly used in the synthesis of peptides. For the acylation, the carboxyl group of the acylating agent can be activated by conversion to the acid chloride or to a mixed anhydride with e.g. a lower alkyl chloroformate. The carboxyl group may also be activated by conversion to the 2,4-dinitrophenyl or N-hydroxysuccinimidoyl esters. If an ester of cephalosporin chem is used, e.g. benzhydryl, t-butyl, trichloroethyl or a benzyl ester, the protected phenylglycine can be directly coupled to the 7-amino group using a carbodiimide such as dicyclohexylcarbodiimide. Alternatively, the protected phenylglycine may be activated for condensation with the desired cephalosporin core by first reacting it with carbonyl diimidazole or its equivalent.

The reaction of compounds of formula (XI) with thiols of formula (III) is preferably carried out at a pH near neutrality. The solvent is preferably water or water acetone. The reaction can be carried out at temperatures of approx. room temperature to the boiling point of the solvent, the reaction time varying with the temperature, the solvent and the reaction participants. The reaction product is isolated by gently acidifying the reaction mixture and extracting with an appropriate organic solvent.

An α-amino group present at the 7-position of the compound used as starting material must be protected with a readily removable group such as t-butoxycarbonyl, carbobenzyloxy or trichloroethoxycarbonyl. After the reaction, the protecting group is removed in the usual manner.

The starting materials are described in the literature or can be obtained in known ways.

It will be seen that due to the asymmetric α-carbon atom in the 7-acetamido group, optical isomers exist. The D isomer is in the preferred isomer, but the L isomer and racemic mixture are also within the scope of the invention.

The compounds are formulated for injectable or oral preparations in the same way as other antibiotic cephalosporins. They are administered by injection or orally to prevent or treat bacterial infections at doses that may vary with the nature and severity of the disease and the age, weight and condition of the patient.

Due to the presence of both an amino group and a carboxylic acid group in the cephalosporin compounds of the invention, it is possible, by standard methods, to produce both acid salts and base salts of pharmaceutically usable non-toxic acids and bases as well as the zwitterionic forms of the compounds. When salts are obtained, they are readily converted to the zwitterions in known ways.

Salts of compounds containing only one acid function are also prepared using pharmaceutically useful non-toxic bases. It will be understood that all these salts are within the scope of the invention.

The following examples are intended to further illustrate the process.

Example 1 7- (ci-amino-p-hydroxyphenylacetamido) -3- (1,2,3-triazol-4-ylthio = methyl) -3-cephem-4-carboxylic acid.

To a stirred solution of 10.75 g (0.0375 mole) of N-t-butoxycarbonyl-p-hydroxyphenylglycine in 150 ml of dry tetrahydrofuran was added 5.2 ml (0.0375 mole) of triethylamine. The mixture was cooled to -10 ° and then 4.92 ml (0.0375 mole) of isobutyl chloroformate was added dropwise over 10 minutes. The reaction mixture was stirred at -10 ° C for 7Q minutes and then a cold solution of 7-ACA (10.1 g, 0.0375 mol) in 140 ml of 50% aqueous tetrahydro-furan and 6.75 g ( 0487 moles of triethylamine added over 15 minutes. The reaction was stirred at -5 to 0 ° for 1 hour and at room temperature for 2 hours. The organic solvents were evaporated and 150 ml of water were added to the aqueous residue. The solution was extracted with ethyl acetate and the aqueous phase was separated, covered with fresh ethyl acetate, acidified to pH 2.8 and filtered. The phases were separated and the acidic solution re-extracted with ethyl acetate. The extracts of the acidified aqueous solution were combined, dried and evaporated to give the N-butoxycarbonyl derivative of 7- (α-amino-β-hydroxyphenylacetamido) cephalosporanoic acid.

1429 13 8

A mixture of 3.0 g (0.00493 mole) of the above product in 30 ml of a pH 6.4 phosphate buffer was treated with 1.085 g (0.01233 mole) of NaHCO 3 and then 0.748 g (0.0074 mole). 4-mercapto-1,2,3-triazole. The solution was heated to 70 ° and stirred at 70 703 ° for 2.75 hours. The solution was cooled, filtered and acidified to pH 2.5 to give a residue. The solvents were decanted and the residue washed with water. The product was dissolved in ethyl acetate, washed with water, dried and evaporated to the N-protected product, which was re-precipitated by acetone chloroform.

The protected product was stirred at 0 to 5 ° with a 9: 1 tri = fluoroacetic anisole solution for 70 minutes. The solvents were evaporated and the residue was poured into 350 ml of ether with vigorous stirring. The solid was collected, dissolved in water and stirred with basic ion exchange resin (Amberlite IR-45, an anionic polystyrolamine resin) until the pH became constant. The resin was filtered off and the aqueous solution lyophilized to give the product. Calcd. For C18H18N6 ° 5S2'2H2O: C 43'37 'H 4.45, N 16.86.

Found: C, 43.67; H, 4.14; N, 16.62.

IR: Amax (nujol) 3.2; 5.65; 5.90 µ. NMR (TFA) δ 3.8 (S, 2H), 4.2 (q, 2H), 5.3 (d, 1H), 5.5 (d, 1H), 5.8 (q, 1H), 7.4 (q, 4H), 8.5 (s, 1H).

Example 2 7- (D-α-amino-p-hydroxyphenylacetamido) -3- (4-methyl-1,2,3-triazol-5-ylthiomethyl) -3-cephem-4-carboxylic acid.

5-Benzamido-4-methyl-1,2,3-thiadiazole (6.60 g, 0.03 mol, prepared as described in Berichte 99, 1629 (1966)) was combined with 60 ml of 2N NaOH and the solution heated at reflux overnight. After approx. After 25 hours of heating, the reaction mixture was cooled in ice and 120 ml of 2N HCl was added with stirring. The mixture was refrigerated for a weekend. The precipitated solid (benzoic acid) was then filtered off while the mixture was still cold. The solid was washed with a little water and the pH of the filtrate was adjusted to 3.0 with 10% NaOH. The aqueous solution was extracted with ethyl acetate four times. The extracts were dried and filtered. Sodium 2-ethylhexanoate was added until no more precipitation occurred. The solid sodium salt of 5-mercapto-4-methyl-1,2,3-triazole was filtered off and then dried under vacuum.

To a stirred suspension of 6.78 g (0.013 mol) of 7- (at-butoxycarbonyl-amino-p-hydroxyphenylacetamido) cephalosporanoic acid and 3.82 g (0.02 mol) of the sodium salt of 5-mercapto-4-methyl 1,2,3-triazole in 1Q0 ml of a pH 6.4 phosphate buffer was added 1.09 g (0.013 mol). NaHCO ^. The mixture was heated to 70 ° for 4 1/2 hours, the reaction was controlled by TLC, allowed to cool, and the resulting gum was stirred with water and any insoluble matter filtered. The solution was covered with ethyl acetate and refrigerated overnight.

The layers were then separated and the aqueous layer acidified to pH 3.0 with 3N HCl. It was then extracted several times with ethyl acetate and the extracts dried and evaporated. The resulting gum was triturated with ether to give 2.69 g of solid. Small amounts were then re-precipitated twice by methanol-ether, and then the desired material was precipitated with petroleum ether. The resulting solid (1.75 g) was chromatographed on 100 g of silica gel using 90: 10: 3 chloroform: methanol: formic acid. The column gave 0.80 g of the t-butoxycarbonyl derivative of the title compound.

0.80 g (0.00139 mol) of the above derivative was placed in a small round bottom flask with a drying tube and immersed in an ice bath. Ca. 10 ml of cold trifluoroacetic acid was added and the mixture was stirred in the cold for approx. 15 minutes and then evaporated for 15 minutes. The mixture was poured into ca. 100 ml of ether and the resulting solid collected and dissolved in ca. 25 ml of water. It was then stirred with IR 45 Amberlite resin, a basic ion-exchange polystyrene resin (washed three times) until the solution reached a pH of about 5.5. The resin was filtered off and the solution lyophilized overnight to give the title product.

Calcd. For C18 H20 N6 O5 S2.2 3/4 H2 O: C 43.38, H 4.89, N 15.97.

Claims (1)

Found: C 43.75, H 4.80, N 15, 27 IR: 5.69 and 5.98 µ. Ή NMR (trifluoroacetic acid, tetramethylsilane): δ 3.8 '(S, broad, 2H), δ 4.39 and 4.58 (pairs of doublets, J ~ 12H2, 5H), δ 5.33 (d, J ~ 5H2, 1H), δ 5.66 (m wide, 2H), δ 7.15 and 7.55 (pairs of doublets, J ~ 9H2, 4H), δ 8.5 (S, 1H). Patent Claims Analogous Process for Preparing Cephalosporanic Acid Derivatives of Formula Ί3Ω-Μ \ -CHC0im - [- f ^ S is optionally substituted with an alkyl = group of 1-4 carbon atoms, characterized in that (1) an acetoxymethylcephalosporin compound of the formula ίΛίΗη- ^ oJ-η ^^ _ 0Η2οσο0Η3 (11) C00H wherein B1 is HO- / VCHCO wherein M is suitably protected, v = / 1H 2 if necessary, or H is reacted with a heterocyclic thiol compound of formula HS-R (III) wherein R is as defined above and (2) when R H, the resulting compound is acylated with a p-hydroxyphenylacetic acid compound of formula H0- (f VoHCOOH (IV) bh2) or an acylating or activated derivative thereof wherein NH