Alkyl phosphorus dihalide preparing method

Abstract

The invention relates to an alkyl phosphorus dihalide preparing method and belongs to the technical field of preparation of alkyl phosphorus halide. According to the method, hydrocarbon and phosphorus trihalide are taken as raw materials, alkali metal or alkaline-earth metal is taken as the initiator, and reaction is conducted at -30-170 DEG C. The initiator alkali metal or alkaline-earth metal reacts with the phosphorus trihalide to generate phosphorus dihalide free radicals, and free radical reaction is conducted between the phosphorus dihalide free radicals and the hydrocarbon to generate alkyl phosphorus dihalide, halogen hydride and a small amount of alkali halide or alkaline earth halide. The generated halogen hydride is low in solubility in a reaction system, and therefore the halogen hydride can be separated out in the gas form simply by conducting decompression on products. Compared with existing methods of preparing alkyl phosphorus dihalide with hydrocarbon and phosphorus trihalide as raw materials, the method has the advantage that due to the adoption of the initiator alkali metal or alkaline-earth metal, reaction temperature is reduced remarkably, so that the requirements of reaction for temperature and equipment are reduced, and then cost is reduced greatly.

Description

technical field [0001] The invention relates to a preparation method of hydrocarbyl phosphorus dihalide, belonging to the technical field of preparation of hydrocarbyl phosphorus halide. Background technique [0002] As a derivative of phosphorus trihalide, hydrocarbyl phosphorus dihalide has good reactivity and can participate in various chemical reactions, and is widely used in various fine chemical fields such as pesticides and medicines. Such as phenylphosphine dichloride, which can react with alcohol, phenol, aldehyde, amine and other organic substances and is widely used in the preparation of plasticizers, flame retardants, pesticide intermediates, paint batches, defoamers, anti Oxygen etc. Another example is that methyl phosphine dichloride is used as an intermediate for the herbicide glufosinate-ammonium. [0003] There are two main synthesis routes for hydrocarbyl phosphorus dihalides: one is to use halogenated hydrocarbons, phosphorus trihalides, aluminum trihali...

AI Technical Summary

Problems solved by technology

The method has mild reaction conditions and high reaction yield, but the used dihydrocarbyl compounds or tetrahydrocarbyl compounds such as tetraalkyl lead, dialkyl cadmium and other preparation costs are relatively high, making the method less economical, and because the method The use of organic compounds containing lead, cadmium, etc. increases the pressure on environmental protection and makes it difficult to put it into industrialization

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