Synthesis method for cyclopentane-1,2-dicarboximide

Abstract

The invention relates to an organic synthesis method, in particular to a synthesis method for cyclopentane-1,2-dicarboximide. The synthesis method includes: subjecting cyclopentane-1-formamide-2-ammonium formate to heating, azeotropy and dehydration in an organic solvent until no water exists, adding phosphoric acid for industrial use to react to generate cyclopentane-1-formamide-2-formic acid, continuing to heat, dehydrate and cyclize until no water is generated, obtaining a cyclopentane-1,2-dicarboximide reaction mixture, adding toluene to heat, reflux and dissolve, cooling, crystallizing and filtering to obtain cyclopentane-1,2-dicarboximide, wherein the yield is 88%. By the method, the reaction temperature is lowered below 300 DEG C, so that carbonization caused by high-temperature reaction is avoided, product yield and quality are improved, production cost is lowered, production environment is improved, and the synthesis method for cyclopentane-1,2-dicarboximide is suitable for industrial large-scale production.

Description

technical field [0001] The invention relates to an organic synthesis method, in particular to a synthesis method of cyclopentane-1,2-dicarboximide. It belongs to the field of synthesis of pharmaceutical intermediates. Background technique [0002] The existing method for synthesizing cyclopentane-1,2-dicarboximide is to directly synthesize cyclopentane-1-carboxamide-2-ammonium carboxylate at a high temperature of 300-500°C. , 2-dicarboximide, the reaction temperature is high, the carbonization phenomenon is serious, the product yield is low, and the quality is poor. The process yield is about 46%. The reaction formula is as follows: [0003] [0004] Patent ZL200510049977.3 uses cyclopentane-1,2-dicarboxamide to form a salt with acid in an organic solvent, and then rings to prepare cyclopentane-1,2-dicarboximide. The reaction formula is as follows: [0005] [0006] Although the reaction temperature of this method is low at 220-260°C and the yield is as high as 82.15...

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Problems solved by technology

[0006] Although the reaction temperature of this method is low at 220-260°C and the yield is as high as 82.15%, it needs to prepare cyclopentane-1,2-dicarboxamide, cyclopentane-1,2-dicarboxamide and acid to form a salt, and also needs Centrifugal separation, drying and other operations, the reaction steps are long and the operation is complicated

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