Preparation method of 3-difluoro-methyl pyrazole-4-carboxylic acid and 3-trifluoro-methyl pyrazole-4-carboxylic acid

A technology of methylpyrazole and difluoromethyl is applied in the field of preparation of 3-difluoromethylpyrazole-4-carboxylic acid and 3-trifluoromethylpyrazole-4-carboxylic acid, and can solve the problem of reaction Harsh equipment requirements, poor selectivity, waste of fluorine sources, etc.
CN102718712BActive Publication Date: 2015-04-29LANZHOU CHEMSPECWEIER CHEM CO LTD
11 Cites 2 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
LANZHOU CHEMSPECWEIER CHEM CO LTD
Publication Date
2015-04-29

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention provides a preparation method of 3-difluoro-methyl-1H-methyl pyrazole-4-carboxylic acid shown in the formula (I) or 3-trifluoro-methyl-1H-methyl pyrazole-4-carboxylic acid shown in the formula (II), and the method comprises the following steps of: (a) providing a 3-polyfluoro methyl-1H-pyrazole-4-nitrile group shown in the formula (VII); and (b) under the condition of participation of acid or alkaline, carrying out hydrolysis reaction on the 3-polyfluoro methyl-1H-pyrazole-4-nitrile group shown in the formula (VII), thus obtaining the 3-difluoro-methyl-1H-methyl pyrazole-4-carboxylic acid shown in the formula (I) or 3-trifluoro-methyl-1H-methyl pyrazole-4-carboxylic acid shown in the formula (II).
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The present invention relates to the preparation method of compound 3-difluoromethyl-1H-methylpyrazole-4-carboxylic acid and compound 3-trifluoromethyl-1H-methylpyrazole-4-carboxylic acid. Background technique

[0002] Pyrazole amide structure is an important species of fungicides. 3-Difluoromethyl-1H-methylpyrazole-4-carboxylic acid is a common intermediate of the fungicide Bixafen developed by Bayer and Isopyrazam developed by Syngenta; 3-trifluoromethyl-1H-methyl Pyrazole-4-carboxylic acid is an intermediate of the fungicide penthiopyrad developed by Mitsui Chemicals.

[0003] In the prior art, Mitisui's patented method (US2010016612) uses difluoroacetic acid or trifluoroacetic acid as a raw material, under the action of oxalyl chloride or triphosgene, undergoes an addition and elimination reaction with 3-aminoacrylonitrile, and then reacts with methyl hydrazine The reaction proceeds to cyclization and finally hydrolysis to obtain the correspondin...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More