Method for producing o-chloroaniline

Abstract

An o-chloroaniline production method takes o-nitrochlorobenzene as raw material and is characterized in that the o-nitrochlorobenzene is dissolved in alcohol solvent in the presence of catalyst and additive and reacted with hydrogen at 10-120 DEG C and under 0.3-4.0 MPa; the reaction process is continuous reaction; after the completion of the reaction, the o-chloroaniline is obtained through treatment, wherein, the catalyst can be selected from one of the following: Ni / Al2O3, Raney Ni, Pt / C and Pd / C; while the additive can be selected from one, or two, or three of the following compounds: cyclohexylamine, ethylenediamine, ethanolamine, diethanolamine, triethanolamine, pyridine, liquid ammonia, ammonium bicarbonate, ammonium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium carbonate, potassium hydrogen phosphate, potassium dihydrogen phosphate, sodium hydrogen phosphate and sodium dihydrogen phosphate; the dosage of the catalyst takes up 0.05% to 20% of the mass of the o-nitrochlorobenzene; the dosage of the additive takes up 0. 5% to 20% of the mass of the o-nitrochlorobenzene; the alcohol can be methanol or ethanol; the dosage of alcohol takes up 30% to 150% of the dosage of the o-nitrochlorobenzene; the continuous reaction is realized through 1 to 6 tank reactors which are connected in series.

Description

(1) Technical field [0001] The invention relates to a production method of o-chloroaniline, in particular to a method for producing o-chloroaniline by liquid-phase catalytic hydrogenation of o-chloroaniline. (2) Background technology [0002] O-Chloroaniline is an important chemical intermediate in medicine, pesticide, dyestuff, fragrance and polyurethane industry, with a wide range of uses. The synthesis methods of o-chloroaniline include iron powder reduction method, alkali sulfide reduction method, electrolytic reduction method, catalytic hydrogenation method, and hydrogen transfer method. The pollution in the first two synthesis methods is serious, the energy consumption of the electrolysis method is high, the catalyst consumption of the hydrogen transfer method is large, and the cost of methanol is high. [0003] The main problem of catalytic hydrogenation is that hydrodechlorination and tank-type hydrogenation are difficult for continuous industrial production. Dechl...

AI Technical Summary

Problems solved by technology

The pollution in the first two synthesis methods is serious, the energy consumption of the electrolysis method is high, the catalyst consumption of the hydrogen transfer method is large, and the cost of methanol is high

[0003] The main problem of catalytic hydrogenation is that hydrodechlorination and tank-type hydrogenation are difficult for continuous industrial production

Decreased catalyst activity due to dechlorination