Welch, J. Org. Chem., Vol. 41, p. 2220-2222, discloses reacting 6-aminopenicillanic acid (6-APA) with an arylsulfenyl chloride under aqueous conditions to yield a mixture of an aryl sulfenamide and a diarylsulfenimide 6-substituted penicillin.
Nudelman in U.S. Pat. No. 3,907,788 discloses reacting 7-aminocephalosporanic acid (7-ACA) with an equimolar amount of a sulfenyl derivative to yield a 7-sulfenamido cephalosporin.
The combination of an active antibacterial agent and an agent having .beta.-lactamase inhibition are taught in U.S. Pat. Nos. 3,624,225, 3,867,538, and 3,952,094.
Various acylated 7.alpha.-methoxy cephalosporins and 6.alpha.-methoxy penicillins are disclosed as possessing useful antibacterial activity as note for example U.S. Pat. Nos. 3,775,410, 3,780,031, 3,780,033, 3,780,037, 3,843,641, 3,920,639, 3,960,845, 3,978,651, etc.
Also, 7-amino-7-substituted thio-cephalosporins and 6-amino-6-substituted thio-penicillins are disclosed in U.S. Pat. Nos. 3,840,533 and 3,855,233.