Clopidogrel EP Impurity A ((S)-Clopidogrel Carboxylic Acid) Catalogue L620412 CAS 144457-28-3 M.W 307.79 M.F C15H14ClNO2S Specifications FAQs (S)-2-(2-chlorophenyl)-2-(6,7-dihydrothieno[3,2-c]pyridin-5(4H)-yl)acetic acid