Zhejiang Hisun Pharmaceutical Co., Ltd.

Shanghai Institute of Pharmaceutical Industry

Weiwei Xu

Fuli Zhang

Rusheng Bao

Zhezhou Yang

Hua Bai

Pengcheng Qiu

Linyu Pan

Dongming Jiang

Linyong Jin

Hu Pan

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

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Taizhou, China

Weiwei Xu