Zhejiang Tianyu Pharmaceutical Co., Ltd.

Dequan Su

Zhen Wang

Yongjun Tu

Guorong Zhu

Gang Liu

Wei Xiao

Zuwei He

Ruiyun Lv

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,

Preparation method for losartan

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Zhejiang, China

Dequan Su