Method for preparing triethyl phosphite

Abstract

The invention discloses a method for preparing triethyl phosphate .The method comprises the following steps that phosphorus trichloride and absolute ethyl alcohol are adopted as raw materials, methylbenzene is adopted as a solvent, a synthetic reaction is carried out under the action of an acid absorbent, the product is subjected to filtering and vacuum distillation, and refined triethyl phosphate is obtained .Compared with the prior art, 90% or above of a byproduct hydrogen chloride can be removed under the micro-negative pressure condition, the product conversion rate is high, the quality is stable, the quantity of adopted acid absorbent can be reduced, cost can be reduced, recycled hydrogen chloride can be used for other fields, environmental pollution is reduced, and effective resources are reasonably reused; the method for preparing triethyl phosphate is simple, operate is convenient, productivity is high, and the obtained product is high in purity and yield.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a preparation method of triethyl phosphite. Background technique [0002] Triethyl phosphite is a colorless and transparent liquid chemical substance with the molecular formula C 6 h 15 o 3 P, is a class of organophosphorus reagents widely used in pesticides, plastics, pharmaceuticals and other fields. Because it can interact with the oxygen in the air or the organic hydroperoxide generated by the automatic oxidation of plastics, it can play a role in maintaining the stability of plastics, and can also be used as an auxiliary anti-aging agent. It can be used in conjunction with various main anti-aging agents to produce good The synergistic effect is mainly used in soft products such as agricultural film and artificial leather. At the same time, triethyl phosphite is also an important intermediate for the synthesis of pesticides and medicines. In the dye industry, it is used ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are two main methods to produce triethyl phosphite in China using phosphorus trichloride and absolute ethanol as raw materials. One is to use benzene as solvent and N,N-xylaniline as acid binding agent to synthesize Triethyl phosphate, and then pass through ammonia gas to analyze the acid-binding agent; the reacted mixture is washed, layered, dried and dehydrated, and distilled to obtain pure triethyl phosphite. This method has a small production capacity and a short production cycle. Long, large material consumption, unstable product quality, high cost, high discharge of "three wastes", especially waste water is not easy to treat, which is not conducive to environmental protection

The other is to use pure benzene as a solvent and N,N-xylaniline as an acid-binding agent to synthesize triethyl phosphite, and then add soda ash to resolve the acid-binding agent; the reacted mixture is washed, layered, and dried Dehydration, distillation and other processes are used to obtain pure triethyl phosphite. This method has a large production capacity and stable product quality, but the same by-product discharge is large, the "three wastes" are difficult to treat, the waste water has high salt content, high production costs, and is not conducive to environmental protection

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