Zhejiang Hisun Pharmaceutical Co., Ltd.

Shanghai Institute of Pharmaceutical Industry

Rusheng Bao

Fuli Zhang

Hua Bai

Zhezhou Yang

Weiwei Xu

Pengcheng Qiu

Meihua Xie

Daoxin Chen

Rentong Sun

Meng Hu

Hu Pan

Linyu Pan

Dongming Jiang

Linyong Jin

Anping Lai

Intermediate compounds for the preparation of Praziquantel are provided. In particular, the intermediate compounds provided include a compound of formula (IV) and a compound of formula (V). Also provided are processes for preparing the intermediate compounds. Additionally, the raw materials are inexpensive and easy to obtain, the key intermediates are easy to prepare, and the total reaction yield and purity of the obtained target compound Praziquantel is high, so that industrialized mass production of Praziquantel using the intermediate compounds is easy to achieve.

Intermediate compounds for preparation of praziquantel and processes for preparing the intermediate compounds

Disclosed is a preparation method for praziquantel and intermediates thereof. The method includes: obtaining a target product praziquantel by using &#x3b2;-phenethylamine as an initial raw material through a condensation reaction with chloroacetyl chloride, a substitution reaction with ethanolamine, and an acylation reaction with cyclohexanecarbonyl chloride, followed by an oxidation reaction and cyclization reaction. Also disclosed are two key intermediates, namely, a compound of formula IV and a compound of formula V for preparing praziquantel. The preparation method is reasonable and simple in its technological design, uses moderate reaction conditions, and is economical and environmentally friendly. Additionally, the raw materials are inexpensive and easy to obtain, the key intermediates are easy to prepare, and the total reaction yield and purity of the obtained target compound praziquantel is high, so that industrialized mass production is easy to achieve.

Preparation method for praziquantel and intermediate compounds thereof

The present invention provides a key new intermediate (a compound of formula III) of 4-benzyl-1-phenethyl-piperazine-2,6-dione (formula IV compound), a pharmaceutically acceptable salt thereof and a preparation method thereof. The present invention additionally discloses a method for preparing 4-benzyl-1-phenethyl-piperazine-2,6-dione (formula IV compound) from the formula III compound, said method overcoming the shortcomings of current formula IV compound preparation methods, such as low production volumes, low purity, high energy consumption, high costs, and inability to achieve industrialized production, and provides a formula IV compound preparation method which is simple, economical, environmentally-friendly and easy to produce industrially; the reaction solvent of the method is easily recycled and the method can produce the formula IV compound at high production rates and with high purity. 

4-benzyl-1-phenethyl-piperazine-2,6-dione preparation method, and intermediate and preparation method thereof

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

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Taizhou, China

Rusheng Bao