Preparation of 2,3,5,6-tetrafluorobenzyl alcohol

A technology of tetrafluorobenzyl alcohol and tetrafluorobenzonitrile, which is applied in the field of synthesis of chemical intermediates, can solve problems such as increasing costs and increasing environmental pollution, and achieves the effects of reducing by-products, reducing pollution, and cheap and easy-to-obtain raw materials
CN101462928AInactive Publication Date: 2009-06-24ZHEJIANG ZHONGXIN FLUORIDE MATERIALS CO LTD +1
4 Cites 7 Cited by

Patent Information

Authority / Receiving Office
CN Β· China
Current Assignee / Owner
ZHEJIANG ZHONGXIN FLUORIDE MATERIALS CO LTD
Publication Date
2009-06-24
Estimated Expiration
Not applicable Β· inactive patent

Smart Images

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

Abstract

The invention discloses a preparation method of 2, 3, 5, 6-phenylcarbinol tetrafluoride; the preparation method is as follows: the 2, 3, 4, 5, 6-cyanobenzene pentafluoride is taken as initial raw material; cyano group is firstly reduced by catalytic hydrogenation, and then diazotization and hydrolysis reaction are carried out for obtaining hydroxide radical, and then contraposition defluorination is carried out for obtaining the 2, 3, 5, 6-phenylcarbinol tetrafluoride; or the 2, 3, 4, 5, 6-cyanobenzene pentafluoride is taken as initial raw material, the contraposition defluorination is carried out for obtaining the 2, 3, 5, 6-cyanobenzene pentafluoride, the hydroxide radical is reduced by the catalytic hydrogenation, and then the diazotization and the hydrolysis reaction are carried out for obtaining the 2, 3, 5, 6-phenylcarbinol tetrafluoride. The two synthetic routes of the invention both comprises the three reaction steps of catalytic hydrogenation, diazotization and hydrolysis and contraposition defluorination; wherein, in the catalytic hydrogenation process, acid is added for obtaining amine salt, and the diazotization and the hydrolysis reaction are carried out by a one pot process, thus leading byproducts to be greatly reduced, the main products to have high purity and the yield coefficient to reach more than 74 percent; in addition, the whole process has simple operation, mild reaction condition and cheap and easily obtained raw material; catalyst and solvent can be recycled and used, thus reducing pollution, being environment-friendly, having economic value and being suitable for industrialization.
Need to check novelty before this filing date? Find Prior Art

Description

(1) Technical field

[0001] The invention belongs to the field of synthesis of chemical drug intermediates, in particular to a preparation method of 2,3,5,6-tetrafluorobenzyl alcohol. (2) Background technology

[0002] Transfluthrin (transfluthrin) is a pyrethrin insecticide developed and produced by German Bayer Company in the 1980s. It is mainly used for the prevention and control of sanitary pests, and has the effect of quickly striking and killing. At present, few domestic manufacturers produce it, and it is a pyrethroid pesticide with great market prospects. 2,3,5,6-Tetrafluorobenzyl alcohol is an important intermediate in the synthesis of the pyrethroid insecticide transfluthrin. Therefore, the synthesis of 2,3,5,6-tetrafluorobenzyl alcohol has become an important research topic. The structural formula of 2,3,5,6-tetrafluorobenzyl alcohol is as follows,

[0003]

[0004] 2,3,5,6-Tetrafluorobenzyl alcohol

[0005] 2,3,5,6-Tetrafluorobenzyl alcohol is mainly obtain...

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