Production process of tricyclazole

Abstract

The invention provides a production process of tricyclazole, and belongs to the field of pesticide production. The method solves the problems that the utilization rate of formic acid is low in the prior art; the production process of tricyclazole comprises the following steps of S01, putting 30-35% of reaction formic acid into 4-methyl-2-hydrazino benzothiazole, heating to 105-110 DEG C and performing reflux reaction for 2-5h; and S02, after reflux reaction is ended, carrying out reduced pressure distillation, evaporating out and recovering formic acid, wherein the temperature of reduced pressure distillation is 130-160 DEG C; dropwise adding water into the reduced pressure distillation residue, wherein the dropwise adding speed is 30 drops / min to 60 drops / min; carrying out cooling and crystallizing after dropping, wherein the temperature of the cooling crystallization is minus 10 DEG C to 40 DEG C; performing filtering, and then drying on filter cake obtained by filtering at 50-100 DEG C to obtain a tricyrazole crude product; and carrying out refining on the tricyrazole crude product obtained in the step S02 by an ethyl acetate-ethyl alcohol mixed solvent to obtain refined tricyclazole. The method disclosed by the invention is high in yield of the tricyclazole.

Description

technical field [0001] The invention belongs to the field of pesticide production, in particular to a production process of tricyclazole. Background technique [0002] Tricyclazole is a triazole systemic protective fungicide developed and produced by Dow AgroSciences. It is one of the most widely used systemic fungicides for rice crops in China. It has high efficiency, low toxicity and low residue. It can effectively control rice blast. Tricyclazole has a strong systemic property and can be quickly absorbed by the roots, stems and leaves of rice, and transported to all parts of the rice plant. Tricyclazole is mainly used for prevention and protection, and the effect of using it before the onset of disease is better. [0003] There are many routes and methods for synthesizing tricyclazole. At present, most of the production units use o-toluidine as the starting material to prepare through the synthesis route of condensation, cyclization, substitution, and secondary cyclizati...

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Problems solved by technology

[0003] There are many routes and methods for synthesizing tricyclazole. At present, most of the production units use o-toluidine as the starting material to prepare through the synthesis route of condensation, cyclization, substitution, and secondary cyclization. In the final step, the intermediate 4-methyl-2-hydrazinobenzothiazole is prepared by the secondary ring closure of tricyclazole, and the use of formic acid with a concentration of more than 85% is required, and the recovery rate of formic acid after the reaction is only 80%. %, and the concentration is only about 75%, so it cannot be applied directly

And the boiling point of formic acid is close to water, it is difficult to purify to 85%, and there will still be losses in the purification process, and cause a considerable degree of environmental pollution

And the content of tricyclazole in the traditional craft is only about 95% in the existing craft

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