摘要 |
Broad spectrum beta -lactam antibiotics represented by the formula <IMAGE> wherein R is the residue of a carboxylic acid, R2 is H or OCH3, and R4 is hydrogen or C1-C3 alkyl; are obtained by reacting a 7-acylamino-3-halomethyl-1-oxa- beta -lactam ester with the desired 1- or 2-tetrazolemethyl substituted 1H or 2H tetrazole-5-thiol. Alternatively, a 7-amino-3-halo-methyl-1-oxa- beta -lactam ester is first reacted with the bis-tetrazole thiol and then the product is N-acylated with the desired carboxylic acid. |