An improved process for preparing crystalline form-1 of (S)-methyl 2-(2-chlorophenyl)-2-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-yl}acetate bisulfate (clopidogrel bisulfate) of formula I is provided The preparation comprises the straight conversion of an uncyclized material of (S)-methyl 2-[2-(thiophen-2-yl)ethylamino]-2-(2-chlorophenyl) acetate hydrochloride into clopidogrel bisulfate crystalline form-1 without any degradation of clopidogrel base
提供一种改进的制备(S)-甲基2-(2-
氯苯基)-2-6,7-二氢
噻吩[3,2-c]
吡啶-5(4H)-基}
乙酸甲酯双
硫酸盐(clopidogrel bisulfate)I型晶体的过程。该制备包括将(S)-甲基2-[2-(
噻吩-2-基)乙基
氨基]-2-(2-
氯苯基)
乙酸盐的非环化物直接转化为clopidogrel bisulfate I型晶体,没有clopidogrel base的任何降解。