Method for synthesizing N-alkylthiophosphoryl triamide through continuous reaction

Abstract

The invention discloses a method for synthesizing N-alkylthiophosphoryl triamide through a continuous reaction. The method comprises the following steps: 1, mixing thiophosphoryl chloride with an organic solvent, pre-cooling the obtained mixture in a heat exchanger to -5-0DEG C, mixing the material with an aminated compound pre-cooled to -5-0DEG C, and reacting the obtained mixture in a micro-reactor to obtain N-alkylthiophosphoryl dichloride at the outlet of the reactor; and 2, allowing N-alkylthiophosphoryl dichloride to directly enter an ammoniation reactor, carrying out an ammoniation reaction on N-alkylthiophosphoryl dichloride and ammonia gas, and post-processing after the ammoniation reaction is completed to obtain N-alkylthiophosphoryl triamide. N-alkylthiophosphoryl triamide is synthesized through a micro-reaction technology with high mass transfer and heat transfer efficiency, so conversion of intermittence to continuity is realized, the operating step is simplified, and the reaction yield is improved.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and relates to a method for continuously reacting and synthesizing N-hydrocarbyl thiophosphoric triamide. Background technique [0002] N-propyl thiophosphoric triamide and n-butyl thiophosphoric triamide are effective soil urease inhibitors. They can be mixed with urea in a certain proportion to inhibit the activity of soil urokinase, greatly reduce the degradation rate of urea, improve the utilization rate of nitrogen, and provide S, P and other elements at the same time, which has a good soil improvement effect. [0003] The present synthetic method of N-hydrocarbyl thiophosphoric triamide basically all is carried out in reactor, comprises following two kinds of methods: (1) two-step method, patent US4530714, US5883297 and CN101337976A disclose " two-step method " and prepare N -The method of alkyl thiophosphoric triamide, that is, under the condition that the acid-binding agent ex...

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Problems solved by technology

The process is complex, involves low-temperature reaction and long reaction time, high energy consumption, high yield and low cost; (2) one-pot method, CN101412733A discloses a "one-pot method" method for preparing N-hydrocarbyl thiophosphoric triamides, That is to say, under the condition of acid binding agent, phosphorus trichloride reacts with alkyl primary to generate intermediate N-hydrocarbyl thiophosphoryl dichloride and acid binding agent hydrochloride, and then reacts with ammonia gas in the same reaction system to generate the target Product N-hydrocarbyl thiophosphoric triamide, acid binding agent and ammonium chloride

Although this process saves steps, acid-binding agents must be used, and the one-pot method increases the difficulty of post-processing, and the operation steps are cumbersome

[0004] In addition, the two-step reactions involved in this synthesis reaction are all exothermic reactions, and the reaction process is relatively violent. However, the above processes are all carried out in a reactor, and the heat dissipation is poor and it is difficult to avoid back-mixing between the reaction raw materials and the product. Therefore, the two There are many by-products such as n-butylthiophosphoric triamide and tri-n-butylthiophosphoric triamide

Therefore, there are problems such as huge production equipment, difficult post-processing, and increased pressure on environmental protection in production.

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