Production method of imidacloprid

Abstract

A process for preparing imidacloprid includes such steps as mixing imidazole, potassium carbonate, ammonium tetramethyl hydroxide and butanone in jet recirculating reactor, dropping 2-chloro-5-chloromethyl pyridine at 70-90 deg.C for 45-60 min, continuous reaction, cooling to 25-35 deg.C, discharging resultant, filter, vacuum distilling the filtrate to obtain coarse imidacloprid, recrystallizing, water washing, filter and baking. Its advantages are simple structure, low energy consumption, and high selectivity and output rate.

Description

technical field [0001] The invention relates to a method for producing pesticides, in particular to a method for producing imidacloprid. technical background [0002] Currently, 3-methylpyridine heterocyclic insecticides represented by imidacloprid, acetamiprid, fluazifop-p-butyl, and valalifop, have With the advantages of systemic absorption, broad spectrum, high efficiency, low toxicity, low residue, long-lasting effect, and good safety, it has been widely used at home and abroad. Using 2-chloro-5-chloromethylpyridine and N-nitroiminoimidazolidine as raw materials, the synthesis method of directly synthesizing the target product through one-step catalytic condensation is the industrial production route adopted by all imidacloprid raw material manufacturers in China at present. However, they all use a stirred tank reactor for the reaction. The structure of the stirred tank reactor is complex, the power consumption is large, the material is not mixe...

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Problems solved by technology

Using 2-chloro-5-chloromethylpyridine and N-nitroiminoimidazolidine as raw materials, the synthesis method of directly synthesizing the target product through one-step catalytic condensation is the industrial production route adopted by all imidacloprid raw material manufacturers in China at present. However, they all use a stirred tank reactor for the reaction. The structure of the stirred tank reactor is complex, the power consumption is large, the material is not mixed uniformly, and there is likely to be a dead zone in the stirring to make the reaction insufficient, so that the selectivity and yield of the chemical synthesis reaction are not ideal.

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