Synthesis method of 4-aminobenzamide

Abstract

The invention provides a method for synthesizing p-aminobenzamide, comprising the steps of: 1) taking a container, adding p-nitrobenzoic acid, triphosgene and a solvent, after the reaction is completed, collecting the solvent to obtain p-nitrobenzoyl chloride; ) take another reaction vessel, add ammonia and phase transfer catalyst, drop p-nitrobenzoyl chloride toluene solution to obtain p-nitrobenzamide; 3) take the reaction kettle, add p-nitrobenzamide, and add water, Catalyst, obtains described p-aminobenzamide. In the method, the amount of raw materials used is small and the reaction speed is fast. After the hydrogen chloride gas produced by the reaction is absorbed into hydrochloric acid by water, it can be used for other purposes, which effectively reduces the production cost. In the reduction reaction, the iron powder method is replaced by the hydrogenation method, so that the production The cost is reduced, no solid waste is generated, the labor load is greatly reduced, the process is environmentally friendly, and the economic benefit is good.

Description

technical field [0001] The invention belongs to the technical field of chemical product synthesis, and in particular relates to a method for synthesizing p-aminobenzamide. Background technique [0002] 4-Aminobenzamide, CAS number: 2835-68-9, chemical formula C 7 h 8 N 2 O, the molecular weight is 136.15. It is used in the manufacture of organic pigment intermediates, mainly used in the printing of cotton, rayon, and hemp fibers, dyeing and the manufacture of organic pigments for the coloring of inks and pigment printing pastes. [0003] 4-aminobenzamide is an important intermediate of medicine and pigment, and it is most widely used in the production of 170# red pigment. Its preparation generally uses p-nitrobenzoic acid as raw material, and undergoes acid chloride reaction, ammonolysis reaction and reduction reaction production. [0004] At present, the route used by most domestic enterprises to produce p-aminobenzamide is: react with p-nitrobenzoic acid and thionyl c...

AI Technical Summary

Problems solved by technology

[0007] However, in the acyl chloride reaction, the thionyl chloride used is a highly toxic, highly corrosive, and highly irritating fuming liquid, and the amount used is 5 times that of p-aminobenzoic acid. Not only the production conditions are harsh, but the amount used Large, long reaction time, difficult recovery of thionyl chloride, high equipment cost, and large environmental pollution

[0008] Moreover, in the reduction reaction, a large amount of high-quality iron powder needs to be consumed for reduction with iron powder. The collection and transportation of iron powder limit large-scale production to a certain extent. bring great difficulty

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