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Preparation method of tetrafluorobenzene methanol

A technology of tetrafluorobenzyl alcohol and tetrafluorobenzoyl chloride, which is applied in the field of preparation of tetrafluorobenzyl alcohol and benzyl alcohol, can solve the problems of high raw material cost, achieve high activity, reduce the probability of esterification side reactions, and promote reduction The effect of the reaction

Active Publication Date: 2019-02-01
DALIAN QIKAI MEDICAL TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0018] The reaction conditions of this method are relatively mild, but a large amount of I2 is needed, and the raw material cost is very high

Method used

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  • Preparation method of tetrafluorobenzene methanol
  • Preparation method of tetrafluorobenzene methanol
  • Preparation method of tetrafluorobenzene methanol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Example 1 Synthesis of 2,3,5,6-tetrafluorobenzyl alcohol

[0043] Add 3.8g (0.1mol) of NaBH4 and 12g of ethylene glycol dimethyl ether into a 500mL four-necked flask, stir and heat to 78-80°C under nitrogen protection, and reflux for 3 hours.

[0044] After the activation reaction, cool down to 20-30°C, add 300g of water, stir to dissolve, cool down to 5°C, add dropwise 54.6g of 2,3,5,6-tetrafluorobenzoyl chloride obtained in Comparative Example 1 under nitrogen protection. The reaction is strongly exothermic, and gas and solids are generated. The reaction temperature is controlled at 5-15°C, and the dropwise addition takes about 3 hours. After the dropwise addition, the mixture was kept at this temperature for 1 hour.

[0045] Add 100g of dichloromethane and stir for 10 minutes, filter out insoluble inorganic salts, rinse the filter cake with 50g of dichloromethane, combine the filtrates, separate the organic layer, distill and recover the dichloromethane to obtain wh...

Embodiment 2

[0047] Example 2 Synthesis of 2,3,4,5-tetrafluorobenzyl alcohol

[0048] Add 50g (0.258mol) of 2,3,4,5-tetrafluorobenzoic acid to 150mL of thionyl chloride, drop 3 drops of DMF, and heat up to 70°C for reflux reaction. When the solution becomes clear and no gas is released Time to view the end of the reaction. Atmospheric distillation was carried out to recover thionyl chloride, followed by vacuum distillation to obtain 54.1 g of a colorless oily product, 2,3,4,5-tetrafluorobenzoyl chloride, with a yield of 99%.

[0049] Add 4.16g (0.11mol) of NaBH4 and 10g of ethylene glycol dimethyl ether into a 500mL four-neck flask, stir and heat to 78-80°C under nitrogen protection, and reflux for 3 hours.

[0050]After the activation reaction, cool down to 20-30°C, add 300g of water, stir to dissolve, cool down to 5°C, and add 54.1g of 2,3,4,5-tetrafluorobenzoyl chloride dropwise under nitrogen protection. The reaction is strongly exothermic, and gas and solids are generated. The react...

Embodiment 3

[0052] Example 3 Synthesis of 2,4,5,6-tetrafluorobenzyl alcohol

[0053] Add 50g (0.258mol) of 2,4,5,6-tetrafluorobenzoic acid to 150mL of thionyl chloride, drop 3 drops of DMF, and heat up to 70°C for reflux reaction. When the solution becomes clear and no gas is released Time to view the end of the reaction. Atmospheric pressure distillation was used to recover thionyl chloride, followed by vacuum distillation to obtain 2,4,5,6-tetrafluorobenzoyl chloride 54.1 as a colorless oily product with a yield of 99%.

[0054] Add 4.44g (0.12mol) of NaBH4 and 13g of ethylene glycol dimethyl ether into a 500mL four-neck flask, stir and heat to 78-80°C under nitrogen protection, and reflux for 3 hours.

[0055] After the activation reaction, cool down to 20-30°C, add 300g of water, stir to dissolve, cool down to 5°C, and add 54.1g of 2,4,5,6-tetrafluorobenzoyl chloride dropwise under nitrogen protection. The reaction is strongly exothermic, and gas and solids are generated. The reacti...

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Abstract

Belonging to the technical field of organic synthesis, the invention discloses a preparation method of tetrafluorobenzene methanol. The method includes: reacting tetrafluorobenzoic acid with thionyl chloride to produce tetrafluorobenzoyl chloride, then taking tetrafluorobenzoyl chloride as the raw material, and conducting reduction in water with sodium borohydride activated by an ether solvent toobtain tetrafluorobenzene methanol. According to the invention, the ether solvent and sodium borohydride are subjected to complexing to activate sodium borohydride, water is adopted as the solvent forreduction, the reaction yield is high, the reductant sodium borohydride can complete the reaction at a catalytic amount, and the reaction process is greener and more environmentally friendly.

Description

technical field [0001] The invention relates to the preparation of benzyl alcohol, in particular to a method for preparing tetrafluorobenzyl alcohol, belonging to the technical field of organic synthesis. Background technique [0002] Tetrafluorobenzyl alcohol, molecular formula: C7H4F4O molecular weight: 180.10; including 2,3,4,5-tetrafluorobenzyl alcohol CAS: 53072-18-7; 2,4,5,6-tetrafluorobenzyl alcohol and 2,3, 5,6-Tetrafluorobenzyl alcohol, CAS No.: 4084-38-2, also known as tetrafluorobenzyl alcohol, existing methods for synthesizing tetrafluorobenzyl alcohol, more or less have some defects, with 2,3,5 , 6-tetrafluorobenzyl alcohol as an example, mainly divided into the following types: [0003] The first one, using tetrafluorobenzoic acid to directly reduce to tetrafluorobenzyl alcohol [0004] The process route that Bayer Company adopts is also the most classic process route. NaBH is used for reduction, and dimethyl sulfate is used as an auxiliary agent to directly ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C33/46C07C29/147
CPCC07C29/147C07C33/46
Inventor 苑峰姜殿平张洪学孙立芹
Owner DALIAN QIKAI MEDICAL TECH
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