An Alternative Approach to Achieve Enantiopure (3<i>S</i>)-4-Benzyl-3- (4-fluorophenyl)morpholin-2-one: A Key Intermediate of Aprepitant, an NK1 Receptor Antagonist
作者:Naveenkumar Kolla、Chandrashekar R. Elati、Muthulingam Arunagiri、Srinivas Gangula、Pravinchandra J. Vankawala、Yerremilli Anjaneyulu、Apurba Bhattacharya、Sundaram Venkatraman、Vijayavitthal T. Mathad
DOI:10.1021/op700030d
日期:2007.5.1
and alternative synthesis of enantiomerically pure (3S)-4-benzyl-3-(4-fluorophenyl)morpholin-2-one (S)-(+)-2), a key intermediate in the synthesis aprepitant (1), is described. The key resolution of N-benzylglycinamide, (±)-9, is achieved via diastereomeric salt crystallization using (+)-di-p-toluoyltartaric acid (DPTTA) as the resolving agent to furnish (S)-(+)-9. Alkylation of (S)-(+)-9 with 2-bromoethanol
对映体纯的(3 S)-4-苄基-3-(4-氟苯基)吗啉-2-一(S)-(+)- 2的有效替代合成方法,合成中间体的关键中间体(1)进行说明。N-苄基甘氨酰胺的关键拆分(±)-9是通过非对映盐的结晶来实现的,方法是使用(+)-二-对甲苯甲酰基酒石酸(DPTTA)作为拆分剂提供(S)-(+)- 9。(S)-(+)- 9与2-溴乙醇的烷基化反应,然后立体控制环化获得的(S)-(+)- 10得到具有良好收率和对映纯度(> 98%)的所需对映体(S)-(+)- 2。优化反应条件以使该方法稳健,以便以商业规模实施。