The preparation and antibacterial properties of the crude sodium salts of some synthetic penicillins.

In previous communications (l-3) it has been demonstrated that the antibiotic activity (4) produced by heating n-penicillamine (II) hydrochloride hydrate with 2-benzyl-4-methoxymethylene-5(4)-oxazolone (I) in pyridine is due to the synthesis of benzylpenicillin. Because of these results there can be little doubt that, when oxazolones substituted with other groups in the 2 position are condensed with penicillamine hydrochloride in pyridine, the antibiotic activity (1, 4) produced is due to the synthesis of penicillins differing from benzylpenicillin in the nature of the