(6R-(6alpha,7beta(R*)))-7-((Aminophenylacetyl)amino)-3-methyl-8-oxo-5-thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylic acid, (2,2-dimethyl-1-oxopropoxy)methyl ester (Pivaloyloxy)methyl (6R-(6alpha,7beta(R*)))-7-(aminophenylacetamido)-3-methyl-8-oxo-5-thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylate 63836-75-9 EINECS 264-509-1 Pivcefalexin Pivcephalexin