A scaleable route to the pure enantiomers of verapamil

RM Bannister, MH Brookes, GR Evans…

Index: Bannister, Robin M.; Brookes, Michael H.; Evans, Graham R.; Katz, Ruth B.; Tyrrell, Nicholas D. Organic Process Research and Development, 2000 , vol. 4, # 6 p. 467 - 472

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Citation Number: 15

Abstract

A versatile route to single enantiomer verapamil from readily available raw materials is described. The key intermediate, 4-cyano-4-(3, 4-dimethoxyphenyl)-5-methyl hexanoic acid (verapamilic acid), was resolved efficiently with α-methyl benzylamine. Stereochemical integrity at the quarternary carbon centre was preserved through subsequent steps to give either (R)-or (S)-verapamil in good overall yield. This sequence incorporated a selective ...