The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 14, 2017
Filed:
Feb. 15, 2015
Zhejiang Huahai Pharmaceutical Co., Ltd, Taizhou, Zhejiang, CN;
Yongbi Chen, Taizhou, CN;
Wenling Zhang, Taizhou, CN;
Peng Wang, Taizhou, CN;
Jian Chen, Taizhou, CN;
ZHEJIANG HUAHAI PHARMACEUTICAL CO., LTD., Taizhou, CN;
Abstract
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.