Preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol

A technology of tetrafluoroterephthaloyl dimethanol and tetrafluoroterephthaloyl chloride, which is applied in the field of preparation of 2,3,5,6-tetrafluoroterephthaloyl dimethanol, can solve the problem of cumbersome post-treatment process, unfavorable industrial production, Solvent is not easy to recover and other problems, to achieve the effect of simple post-treatment process, low cost and easy disposal

Active Publication Date: 2013-05-22
JIANGSU LIANHE CHEM TECH +4
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to overcome the risk of reaction operation in the existing 2,3,5,6-tetrafluoro-p-phenylenedimethanol preparation method, the post-treatment process is cumbersome, the amount of solvent used is large, the solvent is not easy to recycle, and the cost is high. Waste water containing metals such as zinc and aluminum has serious environmental pollution, which is unfavorable for defects such as industrial production, and a method for preparing 2,3,5,6-tetrafluoro-p-phenylenedimethanol is provided

Method used

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  • Preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol
  • Preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol

Examples

Experimental program
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Embodiment 12

[0019] The preparation of embodiment 12,3,5,6-tetrafluoro-tere-phenylenedimethanol

[0020] Add 7.6g (0.1980mol) of sodium borohydride and 41.3g of chlorobenzene into a 250mL four-neck flask equipped with a thermometer, condenser, and nitrogen protection tube, raise the temperature to 60°C, add 82.5g of chlorobenzene and 27.5g (0.0990mol) of chlorobenzene dropwise The solution of 2,3,5,6-tetrafluoroterephthaloyl chloride was dropped in 0.5 hours. A mixed solution of 2.7 g of chlorobenzene and 0.04 g (0.15 mmol) of iodine was added dropwise, and the drop was completed in 0.5 hours. Incubate at 60°C for 15 hours. Cool down to 50°C, add dropwise to 10% hydrochloric acid aqueous solution by mass percentage (mass percentage refers to the percentage of the mass of hydrogen chloride in the total mass of hydrochloric acid aqueous solution), adjust the pH to 1-2, keep warm for 0.5 hours, and then use a mass percentage of 30 % NaOH aqueous solution (mass percentage refers to the perce...

Embodiment 22

[0021] The preparation of embodiment 22,3,5,6-tetrafluoro-tere-phenylenedimethanol

[0022] Add 9.5g (0.2475mol) of sodium borohydride and 41.3g of chlorobenzene into a 250mL four-neck flask equipped with a thermometer, condenser, and nitrogen protection tube, raise the temperature to 60°C, and add 82.5g of chlorobenzene and 27.5g (0.0990mol) of chlorobenzene dropwise. The solution of 2,3,5,6-tetrafluoroterephthaloyl chloride was dropped in 0.5 hours. A mixed solution of 2.7 g of chlorobenzene and 0.05 g (0.19 mmol) of iodine was added dropwise, and the drop was completed in 0.5 hours. Incubate at 60°C for 8 hours. Cool down to 50°C, add dropwise to 10% hydrochloric acid aqueous solution by mass percentage (mass percentage refers to the percentage of the mass of hydrogen chloride in the total mass of hydrochloric acid aqueous solution), adjust the pH to 1-2, keep warm for 0.5 hours, and then use a mass percentage of 30 % NaOH aqueous solution (mass percentage refers to the p...

Embodiment 32

[0023] The preparation of embodiment 32,3,5,6-tetrafluoro-tere-phenylenedimethanol

[0024] Add 11.4g (0.2970mol) of sodium borohydride and 41.3g of chlorobenzene into a 250mL four-neck flask equipped with a thermometer, condenser, and nitrogen protection tube, raise the temperature to 60°C, and add dropwise 82.5g of chlorobenzene and 27.5g (0.0990mol) The solution of 2,3,5,6-tetrafluoroterephthaloyl chloride was dropped in 0.5 hours. A mixed solution of 2.7 g of chlorobenzene and 0.06 g (0.22 mmol) of iodine was added dropwise, and the drop was completed in 0.5 hours. Incubate at 60°C for 7 hours. Cool down to 50°C, add dropwise to 10% hydrochloric acid aqueous solution (mass percentage refers to the percentage of the mass of hydrogen chloride in the total mass of hydrochloric acid aqueous solution), pH 1 ~ 2, keep warm for 0.5 hours, and then use 30% mass percentage The aqueous solution of NaOH (mass percentage refers to the percentage of the mass of sodium hydroxide in th...

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Abstract

The invention discloses a preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol. The preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol comprises the following step: in a solvent, under the condition of iodine catalysis, carrying out reduction reaction on 2,3,5,6-tetrafluoro-1,4-benzenedicarbonyl chloride and a hydroboron reducing agent so as to obtain 2,3,5,6-tetrafluoro-1,4-benzenedimethanol. The preparation method disclosed by the invention is mild in reaction conditions, high in yield, safe in operation and simple in post-treatment process; the solvent is easy to recycle; the cost is low; wastewater does not contain metal ions, therefore, the method is easy to handle and environment-friendly; and the method is high in product purity, and suitable for industrial production.

Description

technical field [0001] The invention relates to a preparation method of 2,3,5,6-tetrafluoro-tere-phenylenedimethanol. Background technique [0002] 2,3,5,6-Tetrafluoro-tere-phenylenedimethanol is an intermediate in the synthesis of pyrethroid pesticides, and its synthesis methods have been reported at home and abroad. In Chinese patent CN1900039A, Chen Jianhai and others use metal hydride, borohydride or aluminum hydride metal and reducing agent to reduce 2,3,5,6-tetrafluoroterephthaloyl chloride in THF to generate 2,3,5, 6-Tetrafluorotere-phenylenedimethanol. However, it is very difficult to remove the water in the solvent THF, the solvent is not easy to recycle, and will produce peroxides, the risk is very high during distillation, recovery and storage, and the wastewater containing metals such as zinc and aluminum is seriously polluted. The "one-pot method" is adopted "The reaction temperature is not easy to control, the operation is dangerous, the post-treatment proces...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C33/46C07C29/147
Inventor 樊小彬林行军周述勇汪一波沈启富
Owner JIANGSU LIANHE CHEM TECH
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