Intermediate for synthesizing sulfentrazone and synthesis method

A technology for the synthesis of sulfentrazone and its synthesis method, which is applied in the field of intermediates for the preparation of sulfentrazone, can solve the problems of narrow selection range, low total yield, unfavorable continuous improvement, etc., and achieve the effect of easy implementation and high yield

Pending Publication Date: 2022-02-18
浙大宁波理工学院
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The above-mentioned methods are also inevitably obtained first—— In this structure, the benzene ring on the left side and the halogen substitution on the 2 and 4 positions, and the triazolinone ring group on the right side are all indispensable structural groups; The nitro group is introduced into the 5-position of the left benzene ring, and then the nitro group is reduced to an amino group. The overall yield of this technical scheme is low, and it is all substituted with the N-difluoromethyl triazolinone ring—— After the formation, carry out the nitration reaction and the nitro reduction reaction under the condition of mixed acid on the 5-position of the left benzene ring. Since the total yield of these two steps is only about 70%, the cost of sulfentrazone produced by this technical scheme is high
In addition, since the N-difluoromethyl-substituted triazolinone ring is unstable under certain conditions, it is limited by the stability of the group, so that in the presence of the N-difluoromethyl-substituted triazolinone ring The selection range of the method used for nitration and reduction on the benzene ring is narrow, which is not conducive to the continuous improvement of this technical solution

Method used

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  • Intermediate for synthesizing sulfentrazone and synthesis method
  • Intermediate for synthesizing sulfentrazone and synthesis method
  • Intermediate for synthesizing sulfentrazone and synthesis method

Examples

Experimental program
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Effect test

Embodiment 1

[0056] 1. Add 64.80 g (0.40 mol) of 2,4-dichloroaniline and 300 ml of concentrated sulfuric acid to a 500 ml round-bottomed flask, and cool in an ice-water bath; add dropwise a mixture of 160 ml of concentrated sulfuric acid and 16 ml of concentrated nitric acid at 0°C, and dropwise add After completion, the reaction was continued at the same temperature for 2 hours. Then reaction mixture is added in 1500ml ice-water mixture, filter out precipitation, in Virahol / water mixed solvent (the volume ratio of the two in Virahol / water mixed solvent is 3:1, embodiment 2 is the same) 66.24 g (0.32 mol) of 2,4-dichloro-5-nitroaniline were obtained by crystallization in , with a yield of 80%.

[0057] 2. Add 200ml of dichloromethane, 62.10g (0.30mol) of 2,4-dichloro-5-nitroaniline and 66.79g (0.66mol) of triethylamine into a 500ml round bottom flask, and stir well. At room temperature, 86.35 g (0.33 mol) of acetyl chloride was added dropwise to the flask, and after the dropwise addition ...

Embodiment 2

[0080] 1. Add 81.00 g (0.50 mol) of 2,4-dichloroaniline and 330 ml of concentrated sulfuric acid into a 500 ml round bottom flask, and cool in an ice-water bath. A mixture consisting of 180ml of concentrated sulfuric acid and 18ml of concentrated nitric acid was added dropwise at 0°C, and the reaction was continued for 2 hours at the same temperature after the dropwise addition. The reaction mixture was added to 1600 ml of ice-water mixture, the precipitate was filtered off, and crystallized in isopropanol / water mixed solvent to obtain 80.73 g (0.39 mol) of 2,4-dichloro-5-nitroaniline, with a yield of 78%.

[0081] 2. Add 220 ml of chloroform, 62.10 g (0.30 mol) of 2,4-dichloro-5-nitroaniline and 54.51 g (0.69 mol) of pyridine into a 250 ml round bottom flask, and stir evenly at room temperature. At room temperature, 94.2 g (0.36 mol) of acetyl chloride was added dropwise to the flask, and after the dropwise addition was completed, the reaction was continued at room temperatur...

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Abstract

The invention discloses an intermediate for synthesizing sulfentrazone and a synthesis method. According to the method, 2, 4-dichloroaniline is taken as an initial raw material, in the first step of reaction, under the condition of concentrated acid, nitryl is directly introduced to the site-5 of a benzene ring of the 2, 4-dichloroaniline, and then the nitryl is reduced into amino. After the intermediate obtained by the method is introduced into a synthesis route of sulfentrazone, a reaction step of concentrated acid and Fe / HAc is not needed, so that partial decomposition of a triazolinone ring structure is avoided, and the synthesis yield of sulfentrazone is improved. The specific structural formula is shown in the description.

Description

technical field [0001] The present invention relates to the technical field of intermediates for the preparation of sulfentrazone, in particular to an intermediate for the synthesis of sulfentrazone—(N-(2,4-dichloro-5-(4-difluoro Methyl-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)phenyl)acetamide) and its synthetic method. Background technique [0002] A herbicide of difluoromethyltriazolinones——sulfentrazone, whose chemical structural formula is as follows: [0003] [0004] The chemical name of the herbicide is N-(2,4-dichloro-5-(4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2, 4-triazol-1-yl)phenyl)methanesulfonamide. [0005] At present, the synthetic method about this herbicide generally all adopts following basic method: [0006] [0007] (Zhang Yuanyuan, Sun Yonghui, Shi Yueping, Pesticides, 2013, 52(4), 260-262). The method uses 2,4-dichloroaniline as a raw material, and undergoes steps such as diazotization, hydrazone formation, ring formation, N-d...

Claims

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Application Information

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IPC IPC(8): C07D249/12
CPCC07D249/12
Inventor 骆成才李玉麒
Owner 浙大宁波理工学院
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