GB1389195A - Antibiotics - Google Patents

Abstract

1389195 Penicillin and cephalosporin compounds GLAXO LABORATORIES Ltd 14 Jan 1972 [29 Jan 1971 1 Oct 1971] 27242/74 Divided out of 1389194 Heading C2C Novel 7#-acylamidoceph-3-em-4-carboxylic acids and 6# - acylamidopenam - 3 - carboxylic acids and non-toxic salts and esters and corresponding 1-oxides thereof, wherein the acylamido group has the structure where R is a hydrogen atom or an organic group and R<SP>a</SP> is a hydrogen atom or an acyl group, the compounds being anti isomers or a mixture of syn and anti isomers containing at least 75% of the anti isomer, are prepared by reacting a 6-aminopenicillanic acid or a 7- aminocephalosporanic acid with an acid of Formula (VI) wherein R and R<SP>a</SP> have the aforesaid meanings, or an N-acylating derivative of the acid (VI), or by reacting a penicillin or cephalosporin compound of Formula (XI) wherein B is >S or >S#O, R<SP>1</SP> is H or a carboxyl-blocking group and Z is a group in which 1 or 2 carbons link the nuclear S atom and the carbon atom bearing the carboxyl group and which, when it contains 2 carbons, has olefinic unsaturation such that the compound (XI) is a ceph-3-em compound, with the aforesaid acid (VI), if necessary followed by separation of the product into the syn and anti isomers. Acids of the Formula (VI) above are prepared by reacting an appropriate glyoxylic acid with hydroxylamine, and if necessary subsequently reacting the product wherein R<SP>a</SP> is hydrogen with an acylating agent to give a product wherein R<SP>a</SP> is an acyl group. The acid (VI) may be converted to the corresponding acid chloride by treatment with PCl 5 . The inventive penicillin and cephalosporin compounds may be mixed with a pharmaceutically acceptable carrier or diluent to give pharmaceutical compositions having antibiotic activity.