GB838974A - Improvements in or relating to penicillin derivatives - Google Patents

Abstract

The invention relates to penicillins of general formula <FORM:0838974/IV (b)/1> where Pn is <FORM:0838974/IV (b)/2> R1 is hydrogen, methyl or ethyl and R2 is a substituted or unsubstituted acyl group; a substituted or unsubstituted benzene sulphonyl group; an alkoxy carbonyl of formula R3O.CO-in which R3 is methyl, ethyl, propyl or benzyl; a furoyl group or 2 : 4-dinitrophenyl, and salts thereof. Examples illustrate the preparation of the sodium salts of (a) p-benzamido-benzyl penicillin; (b) p-toluenesulphonamidobenzyl-penicillin; (c) p - ethoxycarbonamidobenzyl penicillin; (d) p - 2 : 4 - dinitrophenylaminobenzyl penicillin; (e) p-acetamidobenzyl penicillin; (f) p-phenylacetamidobenzyl penicillin; (g) p - bromoacetamidobenzyl penicillin; (h) p-(phthalimidoacetamido)-benzyl penicillin; (i) p-a -furamidobenzyl penicillin; (j) p-(m-sulphobenzamido)-benzyl penicillin; (k) p-(p-carboxybenzenesulphonamido-)-benzyl penicillin; (l) p-(p - acetamidobenzenesulphonamido) - benzyl penicillin; and (m) p-(N-carbobenzoxyglycyl)-aminobenzyl penicillin. The penicillins are prepared by reacting an aminobenzylpenicillin of general formula <FORM:0838974/IV (b)/3> where R1 and Pn have the meanings given above, with (a) an aliphatic or aromatic acyl chloride or bromide which can be substituted or unsubstituted; (b) an ester of chlorocarbonic acid of general formula R3O-CO-Cl, where R3 is methyl, ethyl, propyl or benzyl; (c) a benzene sulphonyl chloride or bromide which can be substituted or unsubstituted; (d) furoyl chloride; (e) an acid anhydride or mixed acid anhydride derived from an alkyl carboxylic acid having 1 to 3 C atoms inclusive in the alkyl group; or (f) 2,4-dinitrofluorobenzene. A suitable reaction solvent is water and acetone, the temperature being 0 DEG to 30 DEG C. and preferably 15 DEG C., and the pH maintained at 6 to 9 using a buffer such as sodium bicarbonate. Preferably the R2 producing reactant is used in excess. The Provisional Specification covers new penicillins of formula <FORM:0838974/IV (b)/4> where Pn has the meaning given above; R1 is hydrogen or lower alkyl; R2 is a substituted or unsubstituted acyl, aroyl, aralkyl, substituted aryl, alkoxy carbonyl or aralkoxy-carbonyl, carbamido, thiocarbamido group or an aliphatic or aromatic sulphonyl group; or R1 and R2 together represents one of the groups-CH-R4 (where R4 is a substituted or unsubstituted alkyl, aryl or aralkyl group) or is =N-R5 (where R5 is a substituted aryl group); X is oxygen or sulphur or -CH=CH-or-N(R3)-(where R3 is hydrogen or alkyl); and n is 0 or 1.