Preparation method of o-chlorobenzonitrile

Abstract

The invention discloses a preparation method of o-chlorobenzonitrile, which comprises the following steps: 1. weighing 3000kg of o-chlorobenzotrichloride prepared by chlorination, and sucking the o-chlorobenzotrichloride into a cyanation kettle; 2. adding 765kg of ammonia salt to the kettle with 3000kg of o-chlorobenzotrichloride while stirring, finishing the charging, starting a hydrochloric acid absorption system, and starting a heating valve for warming; 3. when the temperature of the kettle rises to 150 DEG C, adding 1kg of catalyst to the kettle, heating while stirring, keeping the inside of the kettle under negative micro-pressure all the time, and absorbing chlorine hydride produced by reaction of materials to obtain the byproduct hydrochloric acid; 4. when the temperature of the kettle reaches 195 DEG C, keeping the temperature for reaction, and carrying out chromatographic tracking detection, wherein the reaction finishes when the content of benzotrichloride is lower than and equal to 0.02%, and the reaction time is about 30 hours in normal cases; 5. and sucking the material which is subject to cyanation into a distillation kettle, and carrying out reduced pressure distillation to obtain the finished product o-chlorobenzonitrile of which the content is greater than and equal to 99%.

Description

technical field [0001] The invention relates to a preparation method of an organic compound, in particular to a preparation method of o-chlorobenzonitrile. Background technique [0002] O-chlorobenzonitrile is an important organic synthesis intermediate, which is mainly used to synthesize 2-cyano-4-nitroaniline, an intermediate of disperse dyes, and can also be used to synthesize the new antimalarial drug nitroquine. [0003] In the existing literature and the commonly used preparation method is: [0004] 1. The reaction of o-chlorobenzoic acid and urea under the action of sulfamic acid, heated to 140°C, reacted violently under the action of stirring, and released a large amount of gas, the temperature automatically rose to 220-230°C, after the reaction was completed, use ammonia water after cooling Clean to neutrality, distill and obtain o-chlorobenzonitrile product, in this preparation method, the sulfamic acid toxicity that uses is bigger, easily injures operator, waste ...

AI Technical Summary

Problems solved by technology

[0004] 1. The reaction of o-chlorobenzoic acid and urea under the action of sulfamic acid, heated to 140°C, reacted violently under the action of stirring, and released a large amount of gas, the temperature automatically rose to 220-230°C, after the reaction was completed, use ammonia water after cooling Clean to neutrality, distill and obtain o-chlorobenzonitrile product, in this preparation method, the sulfamic acid toxicity that uses is bigger, easily injures operator, waste gas, waste water are bigger in the reaction process simultaneously, cause environmental pollution easily, Does not meet clean production requirements

[0005] 2. Trichlorobenzyl is formed by chlorination of o-chlorotoluene, and trichlorobenzyl is passed into NH3 (ammonia gas) under stirring, and o-chlorobenzonitrile is obtained by reacting under high temperature and high pressure conditions. This method is produced under high temperature and high pressure conditions. The safety factor is small, the risk is high, and safety accidents are prone to occur