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Method for preparing 4-methyl-tetrafluoro-benzil-alcohol

A technology of methyltetrafluorobenzyl alcohol and alkyl, which is applied in the field of preparation of 4-methyltetrafluorobenzyl alcohol, and can solve the problems of low yield and the like

Inactive Publication Date: 2003-08-27
江苏省农用激素工程技术研究中心有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above two methods are to prepare 4-methyltetrafluorobenzyl alcohol by hydrogenation reduction reaction to introduce alcohol group function on the substituted benzene ring, and the yield is also low

Method used

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  • Method for preparing 4-methyl-tetrafluoro-benzil-alcohol

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Experimental program
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Effect test

Embodiment 1

[0015] 26.9g (0.01mol) tetrafluoro-tere-phenylenedimethanol monoacetate, 2.0g 5% palladium charcoal and 250ml acetic acid are placed in the autoclave, pass into hydrogen after replacing the air in the autoclave with nitrogen, control the pressure to be 5 atm, and the temperature is 80 ℃ for about 4 hours. Cool, depressurize, suction filter, concentrate the filtrate under reduced pressure, pour into 500ml of water after a little cooling, stir for a while, suction filter, wash with water, dry, and recrystallize petroleum ether to obtain 18.6g off-white solid, MP60~62℃, yield 88 %.

Embodiment 2

[0017] 22.9g (0.10mol), 4-chloromethyltetrafluorobenzyl alcohol, 16.3g zinc powder (0.25mol) and 100ml 50% ethanol are placed in the reaction flask, heated to 60-65°C, and 18g (0.30 mol) acetic acid, heated to reflux for 2 hours after dripping, filtered while hot, the filtrate was heated to evaporate ethanol, cooled, filtered, washed with water, dried, recrystallized from petroleum ether to obtain 14.8g off-white solid, yield 76%.

Embodiment 3

[0019] 5.0g (0.018mol) of 4-bromomethyltetrafluorobenzyl alcohol and 50ml of methanol were placed in a conical flask, and 2.7g (0.072mol) of sodium borohydride was added in batches under magnetic stirring, and the addition was completed in about 2 hours, and heated to Stir at 50°C for 8 hours, cool, add a small amount of dilute hydrochloric acid dropwise, then add 100ml of water and 100ml of toluene, after stirring, separate the toluene layer, evaporate the solvent, and recrystallize petroleum ether to obtain 2.8g of off-white solid with a yield of 80 %.

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Abstract

The invention is a method of making 4-methyl fluorobenzoic alcohol, made by using 4-substituted methyl tetraflurobenzoic alcohol through hydrogenation-reduction reaction.

Description

Technical field: [0001] The invention relates to a preparation method of 4-methyltetrafluorobenzyl alcohol, an important intermediate of pyrethroid insecticide tefluthrin. Background technique [0002] 4-Methyltetrafluorobenzyl alcohol is an important intermediate for the synthesis of the pyrethroid insecticide tefluthrin. GB2066810 introduces a method using LiAlH 4 A method for preparing 4-methyltetrafluorobenzyl alcohol by directly reducing 4-methylbenzoic acid, with a yield of 25%. GB2155464 introduces an improved method, in the presence of quaternary ammonium salts, using NaBH in a water-organic solvent two-phase system 4 Reduction of 4-methyltetrafluorobenzoyl chloride yielded 66%. Above-mentioned two kinds of methods are to prepare 4-methyltetrafluorobenzyl alcohol by the method for introducing alcohol group function on the substituted benzene ring through hydrogenation reduction reaction, and the yield is also all on the low side. ...

Claims

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Application Information

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IPC IPC(8): C07C29/151C07C33/22
Inventor 孔繁蕾周月根
Owner 江苏省农用激素工程技术研究中心有限公司
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