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:
Apr. 08, 2008
Filed:
Dec. 19, 2003
Fuli Zhang, Shanghai, CN;
Meng HU, Shanghai, CN;
Lizhi Zhao, Shanghai, CN;
Mengya GE, Hengdian Dongyang, CN;
Fuli Zhang, Shanghai, CN;
Meng Hu, Shanghai, CN;
Lizhi Zhao, Shanghai, CN;
Mengya Ge, Hengdian Dongyang, CN;
Shanghai Institute of Pharmaceutical Industry, Shanghai, CN;
Zhejiang Kangyu Pharmaceutical Co., Ltd., Dongyang, CN;
Abstract
A new method of preparing memantine hydrochloride, comprising the following steps: reacting 1-bromo-3,5-dimethyl adamantane and urea/formic acid, with formic acid also acting as the solvent; hydrolyzing with aqueous inorganic acid; alkalifying, extracting and acidifying with hydrochloric acid; finally collecting target compound. The method uses inexpensive raw materials and is performed in homogeneous phase under mild conditions. It can achieve high yield and good product purity, and is suitable for macrochemistry. The purity of crude product is 99.0%, and reaches 99.98% after first recrystallization, yield: 69.5%, mp: 332 C (DSC).