Green synthesis method of methyl phosphorus dichloride

Abstract

The invention discloses a green synthesis method of methyl phosphorus dichloride. The method comprises the following steps: by taking phosphorus pentachloride as a catalyst, heating phosphorus trichloride and phosphorus pentachloride into vapor, and preheating to 150-250 DEG C and mixing with methane and then entering a tubular reactor, and reacting for 0.1-1.0s under the conditions that the temperature is at 400-500 DEG C and the pressure is 0.3-1.2MPa, to obtain methyl phosphorus dichloride. After the catalyst is applied to methane and phosphorus trichloride to synthesize methyl phosphorus dichloride, the conversion rate of the phosphorus trichloride is effectively improved to 40%-50%, and the yield is 90%-95%; the adopted catalyst phosphorus pentachloride is decomposed into phosphorus trichloride and chlorine gas, the catalyst and the product is not required for separation, three wastes are not generated during the whole preparation, and all the materials are recycled, so that the resources are saved, the environment is beneficially protected, and the synthesis method is green.

Description

technical field [0001] The invention relates to a synthesis method of organic phosphorus compounds, in particular to a green synthesis method of methyl phosphorus dichloride. Background technique [0002] Methyl phosphorus dichloride is an important intermediate in the synthesis of organophosphorus compounds, and can be used to synthesize a new type of high-efficiency herbicide glufosinate-ammonium. At present, there are two feasible synthetic routes: one is to use methyl chloride and phosphorus trichloride as raw materials, and first form the ligand CH with aluminum trichloride. 3 PCl 4 ·AlCl 3 , and then remove aluminum trichloride to obtain methyl phosphorus dichloride; another route is to react methane and phosphorus trichloride at high temperature to synthesize methyl phosphorus dichloride in one step. These two routes currently have their own advantages and disadvantages. At present, the first route is mostly used in China, and Bayer uses the second route. In additi...

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Problems solved by technology

[0003] For example, Li Yiming et al. proposed a synthetic method using 1,1,2,2-tetrachloroethane as a solvent, methyl chloride, aluminum trichloride and phosphorus trichloride as raw materials, and first reacted at 80°C 6h to get the complex CH 3 PCl 4 ·AlCl 3 , and then reduce it with aluminum at 140°C, and distill it while reacting to obtain the product methyl phosphorus dichloride. The solid waste can be produced in the process of substance reduction; for another example, US4101573 thinks that carbon tetrachloride is used as initiator, and methane and phosphorus trichloride are raw materials, in tubular reactor by controlling residence time, reaction temperature and carbon tetrachloride concentration , when the conversion rate is 10%-30%, the yield is 80%-98%, but this method requires that the conversion rate of phosphorus trichloride is not more than 35%, otherwise the yield will drop significantly, and the initiator tetrachloride used Carbonization can not only initiate the reaction, but also catalyze the decomposition of the product, and carbon tetrachloride is currently used because it has a destructive effect on the ozone layer; another example is the patent US3210418, which reports such as oxygen and nitrogen dioxide as catalysts, and has achieved better results. The effect: the conversion rate is 16%, and the yield is 90%; but when oxygen is used as a catalyst, it is easy to produce corrosive by-products such as alkyl chlorophosphoric acid and phosphorus oxychloride

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