Method of preparing N-ethyl-N-cyanoethyl aniline

Abstract

The invention relates to a method for preparing N-ethide-N-cyanoethyl aniline, mainly comprising the following: (1) a step of condensation reaction, during which, aniline reacts with ethanol in the action of catalyst to generate N-ethyl aniline and N, N- diethylaniline which are separated through distillation to produce pure N-ethyl aniline; (2) a step of addition reaction, during which, the pure N-ethyl aniline obtained in the step (1) reacts with acrylonitrile in the action of the catalyst to produce the N-ethide-N-cyanoethyl aniline; particularly, the condensation reaction is performed in the action of a binary catalyst formed by any two of phosphorus oxychloride, phosphorus trichloride, phosphorus pentachloride, phosphorus trichloride and inorganic acid, and the content of one composition of the binary catalyst is between 5 and 95 percent. In the preparing process, on the basis of the prior process, the binary catalyst is used in the condensation reaction; and the reaction selectivity is improved and the production cost is lowered without changing the reaction condition and so on.

Description

Technical field [0001] The invention relates to a preparation method of N-ethyl-N-cyanoethyl aniline. Background technique [0002] N-ethyl-N-cyanoethyl aniline is mainly used in the synthesis of disperse dyes, and is the main intermediate for the manufacture of disperse yellow, brown, red and other chromatograms. [0003] In the prior art, the preparation process of N-ethyl-N-cyanoethylaniline mainly includes the following steps: [0004] (A), condensation reaction [0005] Under the action of catalyst and pressure from aniline and ethanol, N-ethylaniline and N,N-diethylaniline are produced. The choice of catalyst can be hydrochloric acid, sulfuric acid, phosphorus oxychloride and other compounds. The reaction temperature is 230-250°C, the gauge pressure is 3-4.5MPa, and the reaction time is about 10 hours. The resulting product has an aniline content of 28-31%; N -The content of ethylaniline is 58-60%; the content of N,N-diethylaniline is 8-10%. [0006] (B), distillation [00...

AI Technical Summary

Problems solved by technology

[0012] In the above-mentioned preparation process, in the condensation reaction step, the selectivity of N-ethylaniline only reaches 60%, and the preparation cost of N-ethyl-N-cyanoethylaniline is high