Synthesis method of 2-amino-3, 5-dichloro-N-methylbenzamide

Abstract

The invention relates to a synthesis method of 2-amino-3, 5-dichloro-N-methylbenzamide, which comprises the following steps: 1) adding isatoic anhydride into a solvent A, dropwisely adding a methylamine solution to react, adding water, uniformly stirring, standing for layering, and extracting an organic phase; and 2) slowly adding trichloroisocyanuric acid into the organic phase extracted in the step 1) for reaction, after the reaction is finished, removing the solvent A, adding water, adjusting the pH value to 8-13, performing suction filtration to obtain a white solid, and pulping the whitesolid by using the solvent B to obtain the 2-amino-3, 5-dichloro-N-methylbenzamide. The trichloroisocyanuric acid adopted in the method is high in reaction activity, a product obtained after chlorination reaction forms soluble salt under the alkaline condition, the soluble salt can be dissolved in water and can be well separated, the whole production process is low in cost, the reaction process issimple, production is easy, the yield is high, the finished product purity is high, the total income is high, and environmental pollution is small. Important reference can be provided for industrialproduction.

Description

technical field [0001] The invention relates to the field of medicinal chemistry, in particular to a synthesis method of 2-amino-3,5-dichloro-N-methylbenzamide. Background technique [0002] The intermediate 2-amino-3,5-dichloro-N-methylbenzamide is an important pesticide intermediate used in the synthesis of the bisamide pesticide tetrachlorantraniliprole. Chlorantraniliprole has comparable activity to chlorantraniliprole. However, the intermediate 2-amino-5-chloro-N,3-dimethylbenzamide used by chlorantraniliprole has many synthetic steps and high cost. Patent CN101298451B discloses a 2-amino-3,5-dichloro -N-Methylbenzamide. The starting raw material 2-amino-N-methylbenzamide is relatively expensive, and the cost of N-chlorosuccinimide is relatively high, resulting in a large amount of solid waste. [0003] It is of great significance to study an intermediate 2-amino-3,5-dichloro-N-methylbenzamide which is simple and practical, has high economical efficiency, less side ...

AI Technical Summary

Problems solved by technology

And because the fat solubility of 2-amino-3,5-dichloro-N-methylbenzamide is lower than that of 2-amino-3,5-dichloro-N-isopropylbenzamide, and dichlorohydantoin The chlorination reactivity of (DCDMH) is not high, and using dichlorohydantoin (DCDMH) as the chlorination reagent to prepare 2-amino-3,5-dichloro-N-methylbenzamide often has an incomplete reaction, Usually containing 5-10% monochlorinated 2-amino-N-methylbenzamide, it is necessary to increase the amount of dichlorohydantoin, which will produce a large number of side reactions, and for further chlorinated monochlorinated 2 -Amino-N-methylbenzamide to obtain 2-amino-3,5-dichloro-N-methylbenzamide has no obvious effect, and the 2-amino-3,5-dichloro-N -Methyl benzamide product purity is low

On the other hand, the unreacted monochloro 2-amino-N-methylbenzamide impurity is difficult to remove by adding other reagents for reaction or recrystallization

In addition, the hydantoin obtained from the product of dichlorohydantoin will produce a large amount of solid waste hydantoin, which is difficult to handle. In terms of cost factors, the price of dichlorohydantoin is about 30,000 yuan per ton, and the cost is relatively high. Therefore, in actual production Need a kind of cost badly, the synthetic method of the intermediate 2-amino-3,5-dichloro-N-methylbenzamide that production process is simple, pollutes less

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