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
Synthesis of N-benzyl-3-(S)-(+)-(4-fluorophenyl)-1,4-oxazin-2-one via a crystallisation induced asymmetric transformation
作者:Ramon J. Alabaster、Andrew W. Gibson、Simon A. Johnson、John S. Edwards、Ian F. Cottrell
DOI:10.1016/s0957-4166(96)00531-9
日期:1997.2
The simple and efficient preparation of enantiomerically pure N-benzyl-3-(S)-(+)-(4-fluorophenyl)-1,4-oxazin-2-one by a crystallisation induced asymmetric transformation of its racemate is reported. A key feature of this process is the use of [(1S)-(endo,anti)]-(-)-3-bromocamphor-8-sulfonic acid as both resolving agent for the pure (S)-enantiomer, and in situ racemising agent of the unwanted enantiomer, affording the title compound in high yield. (C) 1997 Elsevier Science Ltd. All rights reserved.