McCarter & English, LLP
Method of refining valsartan comprising more than or equal to 10% D-isomers
The present invention relates to a method of refining valsartan comprising more than or equal to 10% D-isomers, the method comprising: adding a solvent to valsartan comprising more than or equal to 10% D-isomers to dissolve it, then adding a certain amount of inorganic base, separating solids out after salification, distilling a filtrate after filtration, and distilling the filtrate to remove the organic solvent; adjusting the pH of the filtrate with an acid, extracting with an organic solvent, concentrating most of the organic solvent, cooling to crystallize, and obtaining the product. The method enables isomers of the product to be below 0.5%, and produce a yield of more than or equal to 40%, being suitable for industrial production.
ZHEJIANG HUAHAI PHARMACEUTICAL CO., LTD.
C C
C07B C07D
additional inventional
Yongbi Wenling Peng Jian
Chen Zhang Wang Chen