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:
Sep. 16, 2025
Filed:
Jan. 17, 2020
Zhejiang Tianyu Pharmaceutical Co., Ltd., Zhejiang, CN;
Zuwei He, Zhejiang, CN;
Gang Liu, Zhejiang, CN;
Dequan Su, Zhejiang, CN;
Ruiyun Lv, Zhejiang, CN;
Wei Xiao, Zhejiang, CN;
Zhen Wang, Zhejiang, CN;
Guorong Zhu, Zhejiang, CN;
Yongjun Tu, Zhejiang, CN;
Abstract
Provided is a preparation method of losartan, which is prepared by reacting a cyano group-containing intermediate represented by formula (I) with an azide reagent in toluene in the presence of a catalyst; wherein, after the reaction is completed, azide ions are removed by means of the following process: adding water to divide the reaction system into three layers, separating the intermediate layer and adding n-butanol to the intermediate layer for dilution, and adding triphenylphosphine to the resulting diluted solution so as to remove residual azide ions from the diluted solution. The preparation method provided by the present invention does not need to use sodium nitrite, thus fundamentally eliminating the formation of genotoxic impurities nitrosamines. The resulting target product has good purity, high yield, a simple preparation process, mild and easy-to-control operating conditions, and good safety, and is suitable for large-scale industrial production,