Process for synthesizing pure phenyl chloroformate

Abstract

The invention provides a process for synthesizing pure phenyl chloroformate. The process comprises the following steps: firstly, sodium phenolate is obtained; secondly, sodium phenolate whose weight is weighed after reduced pressure distillation by a distillation tower is transferred into a stirred reaction kettle; a circulating freezer is started, the temperature of the stirred reaction kettle is reduced, triphosgene is added into the stirred reaction kettle, and at the same time a catalyst is added into the stirred reaction kettle; the reaction is carried out continuously till the area percentage between phenyl chloroformate and a main by-product diphenyl carbonate is no longer increased; finally, the stirred reaction kettle employs nitrogen for repelling gas, and reduced pressure distillation is carried out in order to obtain phenyl chloroformate. Compared with the prior production process, reaction time is shortened, purity and reaction efficiency are improved.

Description

technical field [0001] The invention relates to the production field of fine chemicals, in particular to a synthesis process of pure phenyl chloroformate. Background technique [0002] Phenyl chloroformate is an important fine chemical intermediate, which is widely used in chemical synthesis and can be used as a polymerization catalyst, plastic modifier, fiber treatment agent, and intermediate of medicine and pesticide. [0003] The main synthesis method of phenyl chloroformate is the phosgene method. Dissolve phenol in chloroform, pass through phosgene under cooling, make the ratio of the absorbed phosgene amount to phenol and other substances, and add other substances dropwise under stirring at 5-10°C The amount of N,N-dimethylaniline. Then dilute with cold water, separate the oil layer, and wash with dilute hydrochloric acid and water successively. After drying with anhydrous calcium chloride, distill to recover chloroform, and then rectify under reduced pressure to col...

AI Technical Summary

Problems solved by technology

The post-treatment of this method is complicated, a large amount of solvent needs to be recovered, the amount of waste water generated is large, and a large amount of N,N-dimethylaniline is used as an acid-binding agent, and the production cost is high.

[0004] A solvent-free synthesis process of pure phenyl chloroformate is currently disclosed, in which molten phenol is directly added to a small amount of catalyst, exposed to light at high temperature, and then phenyl chloroformate with a content greater than 98% is obtained by vacuum distillation. The post-treatment is simple, avoiding the use of a large amount of acid-binding agents and solvents, no process wastewater, and low cost, but it is still difficult to apply this method to industrial mass production

[0005] But existing technology also has by-product production, and production efficiency is also relatively low simultaneously, promptly in production process, phenol can produce by-product diphenyl carbonate (DPC) under the condition of high temperature and acid-binding agent with product phenyl chloroformate ,Right now

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