Method for preparing N-aryl amide without solvent and catalyst

Abstract

The invention discloses a method for preparing N-aryl amide without a solvent and a catalyst. The method is characterized by obtaining the N-aryl amide under solvent-free and catalyst-free action; a molar ratio of substituted meldrum acid and arylamine is (1 to 5) to (5 to 1). According to the method disclosed by the invention, the defects that acyl chloride, anhydride, a dehydration coupling reagent, the solvent, a phase transfer catalyst or a metal catalyst, and the like are required to be adopted in the prior art are overcome; the method has the following advantages that (1) the substituted meldrum acid is used as an acylating agent, so that pre-activation on carboxylic acid or use of the dehydration coupling reagent is avoided; (2) due to easiness in preparation of the substituted meldrum acid, certain difficult-to-obtain or expensive carboxylic acid and activated derivatives are prevented from being used; (3) a solvent-free mode is adopted, so that the use of a toxic organic solvent or emission of wastewater is avoided; (4) no acid, base or metal catalysts exist, the influence of the acid and the base on sensitive groups and equipment and the residue of metal ions in a product are avoided. A synthesis method disclosed by the invention can play an important role in industrial production for preparing the N-aryl amide and particularly for preparing the N-aryl amide with complex carboxylic acid.

Description

technical field [0001] The present invention relates to a method for preparing N-arylamide without solvent and catalyst, in particular, it relates to a method of directly converting substituted Michaelis acid and aromatic amine to prepare N-arylamide under solvent-free and catalyst-free conditions. method. Background technique [0002] As a dominant structural module, amides widely exist in biomolecules such as proteins, natural products, marketed drugs and various intermediates, and are the most basic organic functional groups. Therefore, its synthesis has attracted extensive attention of chemists and has made great progress. Generally, amides are prepared by condensation of carboxylic acids or their derivatives with amines (R. M. de Figueiredo, J. S. Suppo and J. M. Campagne, Chem. Rev., 2016, 116 , 12029-12122; Taylor, J. E. and S. D. Bull. 6.11 N-Acylation Reactions of Amines A2 -Knochel, Paul. Comprehensive Organic Synthesis II (Second Edition) .Amsterdam, Elsevier...

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Problems solved by technology

More recently, thiocarboxylates such as potassium salts have also been used to condense amines to produce amides (H. Liu, et al, ACS Catal , 2016, 6 , 1732-1736), and the reaction can be achieved under light in an open air environment, but requires the use of an expensive ruthenium homogeneous catalyst

Despite the emergence of methods for the synthesis of amides, there are still great challenges in academia and industry

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