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:
Dec. 09, 2025
Filed:
Dec. 28, 2021
Zhejiang Huahai Pharmaceutical Co., Ltd., Linhai Taizhou, CN;
Zhejiang Huahai Licheng Pharmaceutical Co., Ltd., Linhai Taizhou, CN;
Jian Zhang, Linhai Taizhou, CN;
Jichao Wang, Linhai Taizhou, CN;
Xiangqian You, Linhai Taizhou, CN;
Liangwei Qian, Linhai Taizhou, CN;
Tao Zhou, Linhai Taizhou, CN;
Jiaxing Hu, Linhai Taizhou, CN;
Wenfeng Huang, Linhai Taizhou, CN;
ZHEJIANG HUAHAI PHARMACEUTICAL CO., LTD., Zhejiang, CN;
ZHEJIANG HUAHAI LICHENG PHARMACEUTICAL CO., LTD., Zhejiang, CN;
Abstract
The present invention relates to a method for purifying key intermediates of Citalopram, i.e. 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-hydroxymethylbenzonitrile and a salt thereof. The method comprises dissolving crude 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-hydroxymethylbenzonitrile (compound of formula I containing formaldehyde impurity) with an organic solvent, adding a washing solution, controlling the temperature, stirring, leaving to stand for layering, and removing the aqueous layer, so as to obtain a purified organic solution of 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-hydroxymethylbenzonitrile. The method provided by the present invention can effectively remove aldehyde group-containing impurities in the intermediate. The method of the present invention has the advantages of simple operation, cheap raw materials and mild conditions, and is suitable for large-scale industrial production.