Synonyms: 4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylicacid, 6-(2-amino-2-phenylacetamido)-3,3-dimethyl-7-oxo- (6CI);4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,6-[(aminophenylacetyl)amino]-3,3-dimethyl-7-oxo-, [2S-(2a,5a,6b)]- (9CI); DL-Ampicillin; DL-a-Aminobenzylpenicillin; a-Aminobenzylpenicillin