Cefdinir Related Compound B,(6R,7R)-7-(2-(2-aminothiazol-4-yl)acetamido)-8-oxo-3-vinyl-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid,(6R-trans)-7-[[(2-Amino-4-thiazolyl)acetyl]amino]-3-ethenyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic Acid, is the impurity of Cefdinir , a Cephalosporin antibiotic structurally similar to Cefixime. It can be used to treat infections caused by several Gram-negative and Gram-positive bacteria. Impurity in commercial preparations of Cefdinir,Cefdinir Therapeutic