Method for one-step synthesizing N,N-diethyl-m-methyl benzamide in fixed bed

Abstract

The invention discloses a one-step synthesis method of N, N-diethyl-3-methyl-benzamide with a fixed bed, which comprises the steps that: 3-methyl benzoic acid and diethylamine are stirred under a solvent system for reaction to generate a complex salt compound of the 3-methyl benzoic acid and diethylamine, and then materials are fed to the catalyzing fixed bed continuously under constant temperature and constant pressure, then dehydrated continuously to obtain a crude product; the solvent is recovered by distillation under ordinary pressure; finally the pure product of the N, N-diethyl-3-methyl-benzamide is obtained after rectification under vacuum. The molar ratio of the 3-methyl benzoic acid to the diethylamine to the solvent is 1.0: (1.0-15.0): (0-25.0), the mass velocity is 0.1 h<-1> to 20.0 h<-1>, the reaction temperature of the fixed bed is 60 DEG C to 550 DEG C and the reaction pressure of the fixed bed is 0.1 MPa to 5.0 MPa. The synthesis technology has the advantages of short technological process, high conversion ratio, good selectivity, high yield rate, small amount of waste gas, waste water and waste residues, reproducible and recyclable catalyst and low cost.

Description

technical field [0001] The invention relates to a method for one-step synthesis of N,N-diethyl-m-toluamide on a fixed bed, belonging to the technical field of chemical preparation. Background technique [0002] Biting pests such as mosquitoes have always brought serious troubles and even disasters to humans. They not only suck human blood, disturb people's peace, but also infect diseases. In order to eliminate the troubles that biting pests bring to humans, people have discovered and synthesized a variety of insect repellents. Among the various insect repellents known at present, N, N-diethyl-m-methylbenzamide is the The one with the broadest spectrum of physiological activity and the most significant comprehensive repellent effect. It not only shows high repellent activity against mosquitoes, but also has repellent effect on other pests, such as cockroaches, fleas, midges, sand fleas, sand mites, etc. . In addition, it is also a safe insect repellent, and it is effective...

AI Technical Summary

Problems solved by technology

[0009] The above-mentioned three methods of synthesizing N, N-diethyl-m-methylbenzamide mainly have one or more of the following disadvantages: the synthetic reaction is discontinuous, the reaction route is complicated, the conversion rate is low, the selectivity is low, and the yield is low , many wastes, high overall cost

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