The usual procedure for synthesis of the above derivatives n-as to heat aqueous mixtures of the cephalosporanate salt and an alkali salt of the xanthate or dithiocarbamate in molar excess at slightly elevated temperatures for several hours. Nore vigorous reaction conditions were avoided because of hydrolysis of both the p-lactam ring and the acetoxyl group that occurred as competing side reactions. Although the sulfur derivatives so obtained were ...
