Abstract: 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.

Abstract: 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.

Abstract: Disclosed is a preparation method for praziquantel and intermediates thereof. The method includes: obtaining a target product praziquantel by using ?-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.

Abstract: Disclosed is a preparation method for praziquantel and intermediates thereof. The method includes: obtaining a target product praziquantel by using ?-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.

Abstract: 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.

Abstract: The present invention provides a preparation method for (S)-3-(1-(dimethylamino)ethyl)phenyl ethyl(methyl)carbamate, preparation methods for intermediates (S)-1-(3-methoxyphenyl)-N,N-dimethyl-N—((S)-1-phenylethyl)ethanaminium, (S)-1-(3-hydroxyphenyl)-N,N-dimethyl-N—((S)-1-phenylethyl)ethanaminium and (S)-1-(3-(ethyl(methyl)carbamoyloxy)phenyl)-N,N-dimethyl-N—((S)-1-phenylethyl)ethanaminium, as well as a method for using (S)-1-(3-(ethyl(methyl)carbamoyloxy)phenyl)-N,N-dimethyl-N—((S)-1-phenylethyl)ethanaminium to prepare rivastigmine which can be used for the treatment of Alzheimer's disease.

Abstract: 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.

Abstract: The present invention provides the preparation method for (S)-3-(1-(dimethylamino)ethyl)phenyl ethyl(methyl)carbamate (formula X compound), the preparation methods for its intermediates (S)-1-(3-methoxyphenyl)-N,N-dimethyl-N—((S)-1-phenylethyl)ethanaminium (formula VI compound), (S)-1-(3-hydroxyphenyl)-N,N-dimethyl-N—((S)-1-phenylethyl)ethanaminium (formula VIII compound) and (S)-1-(3-(ethyl(methyl)carbamoyloxy)phenyl)-N,N-dimethyl-N—((S)-1-phenylethyl)ethanaminium (formula IX compound), as well as the method for using above mentioned formula IX compound to prepare rivastigmine which can be used for the treatment of Alzheimer's disease. The preparation method for rivastigmine has a reasonable synthetic design with convenient source of raw materials and high total yield, and the product resulted has high chemical and optical purity, which makes it easy for large-scale. industrial production.