On the resolution of fenfluramine

Abstract

Resolution of fenfluramine with (+)-dibenzoyltartaric acid affords (+)-fenfluramine in contradiction of literature claims that (-)-fenfluramine is obtained by use of (+)-dibenzoyltartaric acid. The intermediate dibenzoyltartrate salt has been fully characterized and the absolute configuration of the enantiomers of fenfluramine has been confirmed to be as previously established. Use of (-)-dibenzoyltartaric acid, followed by use of (+)-dibenzoyltartaric acid is the preferred method for obtaining both fenfluramine enantiomers