Studies on Ampicillin and Amoxicillin Derivatives. III. Synthesis of 6-[2-[(Pyrido[2, 3-d] pyrimidin-6-yl) methylamino]-2-phenylacetamido] penicillanic Acid Derivatives, 6-[2-(4-Pyrimidinylamino)-2-phenylacetamido] penicillanic Acid Derivatives and-cephalosporanic Acid Derivatives

Abstract

A series of N-alkylampicillin (2), N-heteroarylampicillin (5) and N-heteroarylcephalexin (6) were synthesized in order to obtain β-lactam detivatives with a broad and orallypotent antibacterial activity similar to that of the injectable N-acylampicillins. 6-[2-[(Pyrido [2, 3-d] pyrimidin-6-yl) methylamino]-2-phenylacetamido] penicillanic acid derivatives (2) were prepared by the reduction of the Schiff base which was derived from the reaction of pyrido [2, 3-d] pyrimidine-6-carboxaldehyde (1) with ampicillin. 6-N-(4-Pyrimidinyl) ampicillin and -cephalexin derivatives (5 and 6) were obtained by the reaction of 4-chloropyrimidine (4) with ampicillin or cephalexin. Compounds 2, 5 and 6 were tested in vitro antibacterial activity and, however, none of them have a broad and potent activity.