METHOD OF OBTAINING OF 7- AMINO- 3- (1- CARBOXYMETHYLTETRAZOL- 5- ILTHIOMETHYL)- 3- CEPHEN- 4- CARBONIC ACID

摘要

Valuable antibiotics are obtained by reacting a compound of the formula in which R<1> is acyl, or a salt or a readily hydrolysable ester thereof with 5-mercapto-1-tetrazoleacetic acid. The latter can be prepared by reacting sodium azide with an isocyanate of the formula ROOCCH2NCS and hydrolysing the resulting thiol ester.