Cefoperazone Impurity 38

2- (carboxy (2- (4- ((2- (carboxy (2- (4-ethyl-2,3-dioxopiperazine-1-carboxamido) -2- (4-hydroxyphenyl) acetamido) methyl) -5- (((1-methyl-1H-tetrazol-5-yl) thio) methyl) -3,6-dihydro-2H-1,3-thiazine-4-carbonyl) oxy) phenyl) -2- (4-ethyl-2,3-dioxopiperazine-1-carboxamido) acetamido) methyl) -5- (((1-methyl-1H-tetrazol-5-yl) thio) methyl) -3,6-dihydro-2H-1,3-thiazine-4-carboxylic acid