An improved process for synthesis of duloxetine hydrochloride (1) having chiral purity greater than 99.9% that is characterized by the following:
(i) preparation of racemic condensed compound (RS)—N,N-di methyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine (4) by reaction of racemic hydroxy compound (2) with 1-fluoronaphthalene (3) in presence of a base such as sodamide, potassium amide or potassium bis(trimethylsilyl)amide (KHDMS) in polar aprotic solvent,
(ii) optical resolution of racemic condensed compound (5a+5b) with di-benzoyl-L-tartaric acid (7, DBTA, R═H) or di-para-anisoyl-L-tartaric acid (7, DATA, R═OCH
3
) to obtain crude (S)—N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine dibenzoyl tartarate salt (8a) or (S)—N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine di-p-anisoyl tartarate salt (9a) respectively,
(iii) optionally purification of crude tartarate salts (8a or 9a) by crystallization,
(iv) optionally purification of duloxetine hydrochloride (1) by crystallization and
(v) racemization of undesired (R)—N,N-di methyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine (5b) by treatment with base potassium bis(trimethylsilyl)amide (KHDMS) to obtain racemic mixture of condensed compounds (5a and 5b).
一种改进的杜
氯西泮盐酸盐合成方法(1),其手性纯度大于99.9%,其特征如下:(i)通过在极性无
水溶剂中使用碱,如
氢化钾铵、
钾铵或叔丁基三甲基
硅酰胺
钾盐(KH
DMS),以
1-氟萘(3)与外消旋羟基化合物(2)反应制备外消旋缩合物(RS)-N,N-二甲基-3-(1-
萘氧基)-3-(2-
噻吩基)
丙胺(4),(ii)使用二苯乙酰-
L-酒石酸(7,D
BTA,R = H)或二对
甲氧基苯基-
L-酒石酸(7,
DATA,R = OCH3)对外消旋缩合物(5a + 5b)进行光学分辨,从而获得粗品(S)-N,N-二甲基-3-(1-
萘氧基)-3-(2-
噻吩基)
丙胺二苯乙酰
酒石酸盐(8a)或(S)-N,N-二甲基-3-(1-
萘氧基)-3-(2-
噻吩基)
丙胺二对
甲氧基苯基
酒石酸盐(9a),(iii)可选择通过结晶纯化粗品
酒石酸盐(8a或9a),(iv)可选择通过结晶纯化杜
氯西泮盐酸盐(1),(v)通过使用碱性物质
钾叔丁基三甲基
硅酰胺
钾盐(KH
DMS)对不需要的(R)-N,N-二甲基-3-(1-
萘氧基)-3-(2-
噻吩基)
丙胺(5b)进行消旋,从而获得外消旋缩合物(5a和5b)的混合物。