A Novel Chiral Resolving Reagent, Bis((S)-Mandelic acid)-3-nitrophthalate, for Amlodipine Racemate Resolution: Scalable Synthesis and Resolution Process

A novel bis(( S )-mandelic acid)-3-nitrophthalate ( 1 ), a chiral resolving reagent for the separation of ( S )-(−)-isomers of amlodipine from the racemate thereof, is designed and synthesized. A simple three-step pilot-scale preparation of 1, along with the optimization of a resolution process on the racemate amlodipine, is reported.