7-(4-chloro-3-oxobutyrylamino)cephalosporanic acid, 7β-(4-chloro-3-oxo-butyrylamino)-cephalosporanic acid, (6R)-3-acetoxymethyl-7t-(4-chloro-3-oxo-butyrylamino)-8-oxo-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid, 3-(acetyloxymethyl)-7-[(4-chloro-3-oxobutanoyl)amino]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, 7-(4-chloro-3-oxobutyrylamino)cephalosporin, (6R,7R)-3-Acetoxymethyl-7-(4-chloro-3-oxo-butyrylamino)-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid