Shanghai Institute of Pharmaceutical Industry

Zhejiang Hisun Pharmaceutical Co., Ltd.

Zhejiang Kangyu Pharmaceutical Co., Ltd.

Meng Hu

Fuli Zhang

Hua Bai

Rusheng Bao

Meihua Xie

Daoxin Chen

Rentong Sun

Lizhi Zhao

Anping Lai

Mengya Ge

The present invention provides N-methylethylcarbamino-3-[(S)-1-(methyl-[(S)-1-phenylethyl]amino)ethyl]phenyl ester represented by formula (II) and its preparation method. The present invention also provides (S)-1-(3-methoxyphenyl)-N-methyl-N&#x2014;[(S)-1-phenylethyl]ethylamine and 3-[(S)-1-(methyl-[(S)-1-phenylethyl]amino)ethyl]phenol as intermediates of the compound represented by formula (II), and the use of the compound represented by formula (II) for preparing rivastigmine used for treating Alzheimer disease.

Preparation method of rivastigmine, its intermediates and preparation method of the intermediates

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).

Method of preparing memantine hydrochloride

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Shanghai, China

Meng Hu