Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation method of 2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol

A technology of benzenedimethanol and tetrafluorobenzene is applied in the field of preparation of intermediate 2,3,5,6-tetrafluoro-1,4-benzenedimethanol, and can solve the problems of complicated operation, many side reactions and long synthesis route and other problems, to achieve the effects of cheap and easy-to-obtain raw materials, reduced product costs, and short synthesis routes.

Active Publication Date: 2017-04-19
岳阳中科华昂精细化工科技有限公司 +1
View PDF32 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0024] The purpose of the present invention is to address the above problems, in order to overcome the difficulty of obtaining raw materials in the existing preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol, expensive raw materials, long synthetic route, many side reactions, Due to the defects of cumbersome operation and high product cost, a preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol is provided

Method used

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
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of 2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol
  • Preparation method of 2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol
  • Preparation method of 2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] The preparation of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol comprises the following steps:

[0045] a. Synthesis of 1,4-bis(trichloromethyl)-2,3,5,6-tetrachlorobenzene (II)

[0046] Add 53.1g p-xylene (I) and 0.5g iron powder to a 250mL four-neck flask equipped with a stirrer, a thermometer, a condenser tube (the end is connected to an exhaust gas absorption device) and a gas inlet tube, raise the temperature to 110°C, and open the The sodium lamp light source at 10cm beside the flask immediately introduces chlorine gas through the airway. Control the temperature at 110-115°C, stir under light, and feed 360g of chlorine gas. After stopping the chlorine gas for 5 minutes, turn off the light source. Then nitrogen gas was introduced under stirring for 15 minutes to drive off residual hydrogen chloride to obtain 201.0 g of compound II.

[0047] b. Synthesis of 1,4-bis(methoxychloromethyl)-2,3,5,6-tetrafluorobenzene(III)

[0048]In a 500mL four-neck flask equipped with ...

Embodiment 2

[0052] In step a, keeping other conditions unchanged, 1.6 g of ferric chloride was used instead of iron powder, the temperature was controlled at 90-95° C. and chlorine gas was introduced into the reaction to obtain 182.5 g of compound II.

[0053] In step b, keeping other conditions unchanged, in a 1000 mL four-necked flask, 600 g of n-butanol was used instead of methanol, 90.5 g of potassium fluoride was added, and the temperature was raised to 120° C. for 6 h to obtain 33.9 g of compound III.

[0054] In step c, keep other conditions unchanged, add 600g n-butanol, 1.0g Pd / C, 33.9g compound III and 79.1g pyridine, react at 115-120°C and hydrogen pressure 5.0MPa to obtain 14.3g compound IV, The purity by HPLC was 96.1%.

Embodiment 3

[0056] In step a, keeping other conditions unchanged, 3.0 g of aluminum trichloride was used instead of iron powder, the temperature was controlled at 50-55° C., and chlorine gas was introduced into the reaction to obtain 171.3 g of compound II.

[0057] In step b, keeping other conditions unchanged, 150 g of ethanol was used instead of methanol, 58.0 g of potassium fluoride, and the temperature was raised to 80° C. for 12 hours to obtain 32.7 g of compound III.

[0058] In step c, keep other conditions unchanged, add 500g methyl tert-butyl ether, 5.0g Raney Ni, 32.7g compound III and 31.6g pyridine, react at 180~185°C and hydrogen pressure 3.0MPa to obtain 13.1g compound IV, the purity detected by HPLC is 96.5%.

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

PUM

No PUM Login to View More

Abstract

The invention discloses a preparation method of 2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol, and belongs to the technical field of fine chemical synthesis. The preparation method is characterized by comprising the following reaction steps that (1) chlorine is led into paraxylene under catalyzing of a catalyst and irradiation of visible light to achieve chlorination, then nitrogen is led in to expel residual hydrogen chloride gas, and 1,4-dual(trichloromethyl)-2,3,5,6-tetrachlorobenzene is obtained; (2) the 1,4-dual(trichloromethyl)-2,3,5,6-tetrachlorobenzene and potassium fluoride are subject to fluorization and alcoholysis in an alcohol solvent, the solvent is recycled through reduced pressure distillation, washing is carried out the neutral state is obtained, drying is carried out, and 1,4-dual(silane oxygen methyl chloride)-2,3,5,6-tetrachlorobenzene is obtained; and (3) hydrogen is led into the 1,4-dual(silane oxygen methyl chloride)-2,3,5,6-tetrachlorobenzene in a solvent containing a metal catalyst and an acid-binding agent to be subject to catalytic hydrogenation reduction, an upper-layer organic phase is subject to cooling, suction filtration and drying to obtain the2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol. The preparation method has the beneficial effects that the raw materials are low in price and easy to obtain, the synthetic route is short, operation is easy and convenient, and the product cost is low.

Description

technical field [0001] The invention belongs to the technical field of synthesis of fine chemicals, and in particular relates to a preparation method of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol, an intermediate of pyrethroids. Background technique [0002] 2,3,5,6-Tetrafluoro-1,4-benzenedimethanol is an important intermediate in the synthesis of highly efficient and low-toxic fluorine-containing pyrethroids (tefluthrin and perfluthrin). Its disclosed synthetic technology routes mainly include the following five types: [0003] (1) Use 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid or its derivatives as raw materials to obtain 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid through reduction reaction Methanol: [0004] [0005] Among them, there are five synthetic routes: [0006] The route ① disclosed in WO9312096, WO2007086330, US6759558, DE3714602, and EP1247792 uses 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid as raw material and reduces it with sodium boroh...

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

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C07C33/46C07C29/58
CPCC07C17/14C07C29/58C07C41/16C07C33/46C07C43/225C07C25/125
Inventor 蒋玉仁吴海让吴海燕
Owner 岳阳中科华昂精细化工科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com