Semisynthetic cephalosporins. Synthesis and structure-activity relationships of 7-(1-pyrryl)- and 7-(1-indolyl)acetamidocephalosporin derivatives.

A series of 1-pyrrole- and 1-indoleacetamido derivatives of 3-heteroaryl-substituted cephalosporins was prepared. The most active compound in the series was 7-[[2-(1-pyrryl)acetyl]amino]-3-[[(1-methyltetrazol-5-yl)thio]-methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (6), which showed comparable potency in vitro and in vivo to that of cefazolin, and, in addition, was more potent than cefazolin against Enterobacter sp. and Providencia stuartii.