Method for the enantiomoeric separation of optical active amlodipine
AssigneeShijiazhuang Pharmaceutical Group Ouyl Pharma. Co., Ltd.
InventorsNanping Zhong, Xianfeng Zhao, Hui Ma, Yujie Chen
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Abstract
The present invention relates to the preparation of the (S)-(−)-amlodipine and (R)-(+)-amlodipine by means of enantiomeric separation of racemic amlodipine mixture, in which, L- or D-tartaric acid is used as resolution agent, and organic solvent containing 2-butanone is used as solvent. The 2-butanone used in the present invention has the advantage of low boiling point, low toxicity, litter pollution, and the method is suitable for large-scaled production.
Claims12
A method for preparing (S)-(−)-amlodipine comprising:
- dissolving racemic amlodipine and L-(+)-tartaric acid in an organic solvent containing 2-butanone to yield (S)-(−)-amlodipine-L-(+)-tartrate precipitate by reaction;
- separating the precipitate;
- recrystallizating the precipitate by using a lower alcohol solvent to obtain a solid;
- adding a lower alkyl halide into the solid;
- and neutralizing with an aqueous alkali to give (S)-(−)-amlodipine.
A method for preparing (R)-(+)-amlodipine comprising:
- dissolving racemic amlodipine and D-(−)-tartaric acid in an organic solvent containing 2-butanone to yield (R)-(+)-amlodipine-D-(−)-tartrate precipitate by reaction;
- separating the precipitate;
- recrystallizating the precipitate by using a lower alcohol solvent to obtain a solid;
- adding a lower alkyl halide into the solid;
- and neutralizing with an aqueous alkali to give (R)-(+)-amlodipine.
Dependencies are inferred from the claim text.