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Process for synthesizing levopraziquantel

A technology of L-praziquantel and synthesis process, applied in the direction of organic chemistry and the like, can solve the problems of high production cost, many toxic reagent raw materials, poor product quality, etc., and achieves reduction of synthesis cost, simple and controllable operation method, and stable product quality. Effect

Inactive Publication Date: 2016-07-13
JIANGSU CHENGXIN PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, how to solve the technical problems of high production cost, poor product quality, and many toxic reagent raw materials in traditional production has always been a bottleneck for technicians in this industry to overcome

Method used

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  • Process for synthesizing levopraziquantel
  • Process for synthesizing levopraziquantel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] (1) Add sulfuric acid (250g) dropwise to a solution of N-(2-phenyl)ethyl-2-{(acetal acetal)amino}acetamide (500g) in dichloromethane, stir the reaction, and add to the reaction Add 30% liquid caustic soda dropwise to the liquid, filter and separate the liquids, and concentrate the lower layer filtrate to dryness to obtain compound 2.

[0030] (2) Add methanol to compound 2, stir to dissolve, add L-tartaric acid (250g) to the solution, heat up and stir until the material is completely dissolved, cool down to crystallize, filter, add the resulting solid to methanol, and heat up to 40-60°C Stir to make a slurry, cool down to -10-10°C to cool and crystallize, and filter to obtain compound 3.

[0031] (3) Add drinking water and dichloromethane to the obtained solid, stir to dissolve, add NaHCO3 aqueous solution to the solution, adjust the pH of the reaction solution to neutral, and add cyclohexylformyl chloride (50g). Stir the reaction, separate the liquid, collect the lowe...

Embodiment 2

[0049] (1) To a toluene solution of N-(2-phenyl)ethyl-2-{(acetal acetal)amino}acetamide (500g), add methanesulfonic acid (2000g) dropwise, stir the reaction, and add to the reaction Add 30% liquid caustic soda dropwise to the solution to neutrality, filter, separate the liquids, and concentrate the filtrate to dryness to obtain Compound 2.

[0050] (2) Add ethanol to compound 2, stir to dissolve, add L-tartaric acid (500g) to the solution, heat up and stir until the material is completely dissolved, cool down to crystallize, filter, add the resulting solid to ethanol, and heat up to 40-60°C Stir to make a slurry, cool down to -10-10°C to cool and crystallize, and filter to obtain compound 3.

[0051] (3) Add drinking water and toluene to the obtained solid, stir to dissolve, add triethylamine to the solution, adjust the pH of the reaction solution to neutral, and add cyclohexylformyl chloride (500g). Stir the reaction, separate the liquid, collect the organic phase, concentra...

Embodiment 3

[0053] (1) In the dichloroethane solution of N-(2-phenyl)ethyl-2-{(acetal acetal)amino}acetamide (100g), add phosphoric acid (500g) dropwise, stir the reaction, and add Add 30% liquid caustic soda dropwise to the reaction liquid until neutral, filter, separate the liquids, and concentrate the lower layer filtrate to dryness to obtain compound 2.

[0054] (2) Add isopropanol to compound 2, stir to dissolve, add L-tartaric acid (200g) to the solution, heat up and stir until the material is completely dissolved, cool down to crystallize, filter, add the resulting solid to isopropanol, and heat up to Stir and beat at 40-60°C, cool down to -10-10°C, cool and crystallize, filter to obtain compound 3.

[0055] (3) Add drinking water and dichloroethane to the obtained solid, stir to dissolve, add NaHCO3 aqueous solution to the solution, adjust the pH of the reaction solution to neutral, and add cyclohexylformyl chloride (100g). Stir the reaction, separate the liquid, collect the orga...

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Abstract

The invention provides a process for synthesizing levopraziquantel. The process is implemented in technical steps as follows: (1) N-(2-phenyl) ethyl-2-[(acetaldehyde acetal) amino] acetamide (compound 1) is subjected to cyclization under the condition of an acid catalyst, and 1,2,3,6,7,11 beta-hexahydro-4H-pyrazino[2,1-alpha] isoquinoline-4-one (compound 2) is generated; (2) L-tartaric acid as a resolution reagent is added to a solvent of the compound 2 generated in the step (1), the mixture is heated and stirred until the mixture is completely dissolved, crystallization is performed at the reduced temperature, a levorotatory compound 2 tartrate crude product (compound 3) is obtained, and the crude product is further heated, beat, cooled, crystalized and purified in the solvent. The process cost is low, the reaction condition is mild, the operation method is simple and controllable, use of a large quantity of toxic reagents is avoided, the product is environment-friendly, good in safety and stable in quality and the product prepared with the synthesis process of levopraziquantel meets medical requirements.

Description

technical field [0001] The invention relates to a process for synthesizing L-praziquantel, belonging to the technical field of medicine and its intermediates. Background technique [0002] Praziquantel is a broad-spectrum anti-parasitic drug, which is very effective against major human schistosomiasis. Since it was first launched in Germany in 1980, it has quickly become the first choice drug for the treatment of schistosomiasis and various parasitic diseases in the world. The advent of praziquantel is a major breakthrough in the treatment of parasitic diseases. At present, it has become the most widely used anti-parasitic drug in the world. [0003] Praziquantel is a racemate composed of two isomers, L-praziquantel and D-praziquantel. Recently, researchers have found through clinical trials that: L-praziquantel is an effective insecticidal component of praziquantel, while D-praziquantel is an ineffective or even harmful component; at the same dose, the clinical efficacy of...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D471/04
CPCC07D471/04
Inventor 刘明明许刘华刘加根邢小飞
Owner JIANGSU CHENGXIN PHARMA
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