Synonyms: 5-Thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylicacid, 3-(chloromethyl)-8-oxo-7-[(phenylacetyl)amino]-, diphenylmethyl ester,(6R,7R)- (9CI);5-Thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid,3-(chloromethyl)-8-oxo-7-[(phenylacetyl)amino]-, diphenylmethyl ester, (6R-trans)-;7-Phenylacetamido-3-(chloromethyl)-3-cephem-4-carboxylic acid diphenylmethylester;