Synthesis method of sulfentrazone intermediate

Abstract

The present invention provides a synthesis method of asulfentrazone intermediate. The methodcomprises: S1) carrying out a nitration reaction on chlorobenzene in a nitration reagent to obtain a mixture of o-chloronitrobenzene and p-chloronitrobenzene, wherein the product does not need to be separated; s2) performing catalytic hydrogenation reaction on the mixture of o-chloronitrobenzene and p-chloronitrobenzene to obtain a mixture of o-chloroaniline and p-chloroaniline, wherein the product does not need to be separated; s3) making the mixture of o-chloroaniline and p-chloroaniline subjected to a diazotization reaction to obtain a mixture of o-chlorophenylhydrazine and p-chlorophenylhydrazine, wherein the product does not need to be separated; s4) performing condensation reaction on the mixture of the o-chlorophenylhydrazine and the p-chlorophenylhydrazine and aldehyde to obtain triazole ring mixtures as shown in a formula I-a and a formula I-b; and S5) carrying out chlorination reaction on the triazole ring mixtures to obtain the sulfentrazone intermediate shown in the formula I. According to the method, 2, 4-dichloroaniline is not used as a raw material, so that the production cost of sulfentrazone is reduced, and the limitation of raw material supply is avoided.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a synthesis method of a sulfentrazone intermediate. Background technique [0002] Sulfentrazone is a herbicide of difluoromethyltriazolinone class, the chemical name is N-(2,4-dichloro-5-(4-difluoromethyl-4,5-dihydro- 3-Methyl-5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide, its chemical structural formula is as follows: [0003] [0004] The benzotriazolinone derivatives substituted by the 5-amino group on the benzene ring are very important pesticide intermediates. Among them, 1-(2,4-dichlorophenyl)-3-methyl-1H-1 ,2,4-triazol-5(4H)-one is the core intermediate in the synthesis of sulfentrazone. Its structural formula is as follows: [0005] [0006] The existing synthesis method of triazolinone intermediates usually takes aniline as the starting material, obtains the corresponding hydrazine through diazotization reduction, then condenses with aldehyde ...

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Problems solved by technology

[0009] Not only that, the isomers and other chlorinated products produced during the production of 2,4-dichloroaniline cannot be well used in downstream production; the oxidation process uses sodium hypochlorite, which not only produces a large amount of waste water, but also generates A large amount of sodium chloride is finally discharged in the form of hazardous waste, which greatly increases the production cost

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