GB1377692A - Antibacterial agents and a process for the preparation thereof - Google Patents

Abstract

1377692 Cephalosporins BRISTOL-MYERS CO 17 Jan 1972 [18 Jan 1971 29 July 1971] 2253/72 Heading C2C Novel cephalosporins having the Formula (I) and salts thereof, wherein Ar is phenyl, 2- thienyl or 3-thienyl, are prepared by reacting a compound of Formula (II) or a salt or easily hydrolysed ester thereof, with an acid of formula wherein Ar is as above and B is a blocking group, or an N-acylating derivative thereof, and then removing the blocking group. The blocking group may be a proton or a #-diketone, or a t-butoxycarbonyl group, a carbobenzyloxy group, a 2-hydroxy-1-naphthcarbonyl group or a trichloroethoxycarbonyl group. The starting materials (II) are also novel, and are prepared by reacting 7-amino-cephalosporanic acid with potassium 5-mercapto-1,2,3- triazole. Sodium D - α - [ - 1 - carbomethoxypropen - 2- yl)amino]-phenylacetate is prepared by condensing D-( - )-phenylglycine sodium salt with methylacetoacetate. Potassium 1,2,3-triazole-5-thiolate is prepared according to the reaction scheme by reacting benzoylisothiocyanate with diazomethane to yield 5-benzamido-1,2,3-thiadiazole, which is hydrolysed with NaOH to 1,2,3-triazole-5-thiol, this product being converted to the said potassium salt by addition of alcoholic KOH. Pharmaceutical compositions having antibacterial activity against gram-positive and -negative bacteria comprise a cephalosporin of Formula (I) above or a non-toxic salt thereof, together with a pharmaceutically-acceptable diluent or carrier.