Patent ID: 9586904
Date: 2017-03-07
CPC Classifications: A61P,C07D

Claim:
1. A method of synthesizing (−)-huperzine A, said method comprising the following steps: (a) Forming a salt between (±)-huperzine A and a chiral acid to give (−)-huperzine A-chiral acid salt; and (b) Basifydng the (−)-huperzjne A-chiral acid salt to give (−)-huperzine A; wherein said chiral acid in step (a) is selected from D-dibenzoyl tartaric acid and D-tartaric acid; wherein step (a) is performed in a solvent selected from acetone-water and ethanol-water; and wherein the ratio of ethanol-water ranges from 1:1 to 5:1.