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. 15, 2022
Filed:
Aug. 09, 2018
Zhejiang Huahai Pharmaceutical Co., Ltd, Zhejiang, CN;
Zhejiang Huahai Tiancheng Pharmaceutical Co., Ltd, Zhejiang, CN;
Zhejiang Huahai Zhicheng Pharmaceutical Co., Ltd, Zhejiang, CN;
Xinlei Chen, Zhejiang, CN;
Zhicheng Hu, Zhejiang, CN;
Liang Zheng, Zhejiang, CN;
Peng Dong, Zhejiang, CN;
Zhejiang Huahai Pharmaceutical Co., Ltd., Zhejiang, CN;
Zhejiang Huahai Tiancheng Pharmaceutical Co., Ltd., Zhejiang, CN;
Zhejiang Huahai Zhicheng Pharmaceutical Co., Ltd., Zhejiang, CN;
Abstract
A preparing method for high-purity levetiracetam, comprising: adjusting the pH of an extracted aqueous layer obtained by dissociating (S)-α-ethyl-2-oxo-1-pyrrolidineacetic acid (R)-methylbenzylamine salt to 5-9; removing water; adding an organic solvent to form a solution and then performing an esterification reaction with ethyl chloroformate or methylchlorofonmate; and carrying out an ammonolysis reaction to obtain the levetiracetam. The method simplifies production process, increases yield, reduces or even avoids the use of triethylamine in the esterification process, and reduces the emission of a great amount of three wastes.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile