Method for preparing p-trifluoromethylaniline by performing high pressure ammonolysis

Abstract

The invention relates to a new method for preparing p-trifluoromethylaniline by performing high pressure ammonolysis. P-trifluoromethyl chlorobenzene serving as a raw material is subjected to high-temperature high pressure ammonolysis reaction in a solvent under the action of a catalyst, liquid ammonia and an acid-binding agent to generate p-trifluoromethyl phenylamine; the catalyst is a mixture of cuprous chloride and copper powder; the acid-binding agent is one or two of inorganic base mixtures of sodium hydroxide and the like, or one or two of organic base mixtures of pyridine and triethylamine; and the solvent is one or two of mixing solvents of methanol, ethanol, polyethylene glycol 300-3,000 and N,N-dimethylformamide. The method has the advantages that the inorganic base, serving as the acid-binding agent, with low cost and easy availability is adopted, the loss of liquid ammonia in the reaction process is greatly reduced, and the production efficiency is improved; and the catalyst can be prepared from organic solvents with the cost as low as that of ethanol and less harm, so that the generation of hydrolysis side reaction is avoided, the purity of the product is high and the quality is high; and raw materials without being totally reacted can be recycled.

Description

Technical field [0001] The invention relates to a method for preparing p-trifluoromethylaniline by high-pressure ammonolysis, and belongs to the technical field of chemical material preparation. The method is suitable for the occasion where p-chlorobenzotrifluoride is used as a raw material, under the action of a catalyst, liquid ammonia, and an acid binding agent, to perform high-pressure ammonolysis in a solvent to prepare p-trifluoromethylaniline. Background technique [0002] P-trifluromethylaniline (p-trifluromethylaniline, abbreviated as PTFMA, CAS accession number is 455-14-1) is an important chemical raw material, especially in pesticides and medicine. After chlorination of p-trifluoromethylaniline, 2,6-dichloro-p-aminobenzotrifluoride can be obtained. It is an important intermediate and used in the pesticide industry to synthesize the high-efficiency and low-toxic insecticide fipronil (Fipronil). Special), fluvalinate, diflubenzuron, herbicides etflurazine, etflurazine,...

AI Technical Summary

Problems solved by technology

The mixture of PTFMA and o-trifluoromethylaniline generated in the reaction, the conversion rate of the reaction is low, and the cost of the trifluoromethyl reagent is too high

[0009] (5) The method of chlorination, fluorine substitution, and reduction after the reaction of p-nitrochlorobenzyl with sulfide is also a method. US Patent US4783562 has a systematic introduction to this method, but this method does not have an advantage in cost at first, and simultaneously reacts Produces highly toxic sulfur chlorides, which are difficult to deal with

Images