GB1314553A - Penicillins - Google Patents

Abstract

1314553 Penicillins BEECHAM GROUP Ltd 30 Sept 1971 [9 Oct 1970] 48117/70 Heading C2A The invention comprises penicillins of Formula I or penicillins of Formula I in which the α- phthalimido group carries one or more substituents, or non-toxic salts and esters of such penicillins. Examples of such penicillins include 6 - [ - D - α - (4 - chlorophthalimido) - phydroxyphenylacetamido] penicillanic acid and the corresponding 4-nitrophthalimido compound. The above penicillins may be prepared by coupling 6-aminopenicillanic acid or a salt or ester thereof with α-phthalimido-p-hydroxyphenylacetic acid or the appropriate α-[substituted phthalimido]-p-hydroxyphenylacetic acid. This coupling reaction may be effected by the use of the acid chloride of the acetic acid derivative or its functional equivalent as an acylating agent for a primary amino group, e.g. the corresponding carboxylic acid bromide, anhydride and mixed anhydride with other carboxylic acids, including monoesters of carbonic acid. Alternatively the 6-APA may be reacted with the intermediates formed from the acid and a condensing agent such as dicyclohexylcarbodiimide or carbonyldiimidazole. A further method of preparing compounds of Formula I comprises using as starting material the correspnding α-aminopenicillin of Formula III and reacting this with a compound of Formula IV wherein R is one or more optional substituents and X and Y taken separately each represent an acylating group for a primary or a secondary amine or X and Y taken together represent a single acylating group which will remove both hydrogen atoms from a primary amine. For example X and Y may each be a chlorine atom or X and Y together may form an N- alkoxycarbonyl group.