Clopidogrel EP Impurity C Sulfate Catalogue L620415 CAS 120202-71-3 M.W 321.82 98.07 M.F C16H16ClNO2S. H2SO4 Specifications FAQs methyl (R)-2-(2-chlorophenyl)-2-(6,7-dihydrothieno[3,2-c]pyridin-5(4H)-yl)acetate, sulfate (1:1)