Semisynthetic beta-Lactam antibiotics. II. Penicillins from alpha-hydrazinoarylacetic acids

A number of penicillins (2) have been synthesized from the alpha-hydrazinoarylacetic acids (4) via the activated chloride hydrochlorides (5) or via the mixed anhydride of the corresponding N2-benzyloxycarbonyl derivatives (6). The penicillins, 2b, e, j, show good activity against gram-positive and gram-negative bacteria and enhanced penicillinase resistance in comparison with ampicillin.