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

Synthesis method of 3, 4, 5, 6-tetrafluorophthalic acid

A technology of tetrafluorophthalic acid and tetrachlorophthalic hydrazide is applied in the field of synthesis of organic compound 3,4,5,6-tetrafluorophthalic acid, and can solve the problem of unfriendly environment and by-products. many problems, long reaction time, etc., to achieve the effects of broad production prospects, improved product yield, and simple post-processing

Inactive Publication Date: 2016-06-22
ZHEJIANG UNIV
View PDF4 Cites 11 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 1. Using literature (Chemical Science and Technology Market, 2006 (07): 30-33), using tetrachlorophthalic anhydride as raw material, tetrafluorophthalic acid is obtained through imidization, fluorination, and sulfuric acid hydrolysis. Poor performance, many by-products, low yield, using sulfuric acid for hydrolysis reaction, the reaction time is about 15 to 40 hours, the production efficiency is low, and a large amount of waste acid is produced to pollute the environment
[0006] 2, adopt literature (JournaloftheChemicalSociety, 1965 (5): 3372), take tetrachlorophthalonitrile as raw material, obtain target product through fluorination, sulfuric acid hydrolysis, this synthetic method raw material source is limited, and hydrolysis reaction can produce nitrile-containing waste water , not friendly to the environment
[0008] In the existing preparation method, there is no bibliographical report of synthesizing the target product with phthalic hydrazide and its analogues as raw materials

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
  • Synthesis method of 3, 4, 5, 6-tetrafluorophthalic acid
  • Synthesis method of 3, 4, 5, 6-tetrafluorophthalic acid
  • Synthesis method of 3, 4, 5, 6-tetrafluorophthalic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] Embodiment 1, a kind of synthetic method of 3,4,5,6-tetrafluorophthalic acid, carries out following steps successively:

[0042] 1), add 16.2g (0.1mol) phthalohydrazide to 50mL oleum (SO 3 The mass fraction is 20%) and 50mL dilute hydrochloric acid (20wt%) in the mixed solution that forms, then add 0.16gKI catalyst and mix and stir, temperature control 50 ℃, control feed 0.3mol chlorine, reaction time 10 hours. The reaction solution after the complete chlorination was cooled (cooled to room temperature) to crystallize, filtered and dried (dried at 80° C. for 60 minutes) to obtain 28.3 g of white crystals of tetrachlorophthalic hydrazide, and the yield was 94.3% (based on o-phenyl Diformyl hydrazide), the content is 99.1%.

[0043] 2) Add 14.53g (0.25mol) of industrial potassium fluoride into a reaction flask containing 50mL of methanol, 50mL of toluene and 50mL of N,N-dimethylformamide mixed solution. The reaction device is equipped with a reflux tube, a thermometer an...

Embodiment 2

[0045] Embodiment 2, a kind of synthetic method of 3,4,5,6-tetrafluorophthalic acid, carries out following steps successively:

[0046] 1), add 16.2g (0.1mol) phthalohydrazide to 50mL fuming sulfuric acid (SO 3The mass fraction is 20%) and 100mL dilute hydrochloric acid (25wt%) mixed solution, then add 0.08gNaI catalyst and mix and stir, the temperature is controlled at 0°C, and 0.4mol chlorine gas is controlled to feed in, and the reaction time is 8 hours. The reaction solution after complete chlorination was cooled and crystallized, filtered and dried to obtain 27.8 g of white crystals of tetrachlorophthalic hydrazide, the yield was 92.7% (calculated as phthalic hydrazide), and the content was 99.0%.

[0047] 2) Add 29.1g (0.5mol) of industrial potassium fluoride into a reaction flask containing 50mL of methanol, 100mL of toluene and 50mL of N,N-dimethylacetamide mixed solution. The reaction device is equipped with a reflux tube, a thermometer and nitrogen replacement devic...

Embodiment 3

[0049] Embodiment 3, a kind of synthetic method of 3,4,5,6-tetrafluorophthalic acid, carries out following steps successively:

[0050] 1) Add 32.4g (0.2mol) phthalohydrazide to 50mL fuming sulfuric acid (SO 3 Mass fraction is 20%) and 150mL dilute hydrochloric acid (28wt%) in the mixed liquor, then add 0.08gI 2 The catalyst was mixed and stirred, the temperature was controlled at 0° C., 1.6 mol of chlorine gas was controlled to flow in, and the reaction time was 8 hours. The reaction liquid after complete chlorination was cooled and crystallized, filtered and dried to obtain 53.1 g of white crystals of tetrachlorophthalhydrazide, the yield was 88.6% (calculated as phthalhydrazide), and the content was 98.8%.

[0051] 2) Add 58.1g (1mol) of industrial potassium fluoride into a reaction flask filled with a mixed solution of 50mL of methanol, 50mL of toluene and 100mL of dimethyl sulfoxide. The reaction device is equipped with a reflux tube, a thermometer and a nitrogen replace...

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 synthesis method of 3, 4, 5, 6-tetrafluorophthalic acid, comprising the following steps: (1) adding phthalylhydrazine into mixed liquid of fuming sulfuric acid and diluted hydrochloric acid, then adding a catalyst I into the mixed liquid and stirring the mixture, controlling the filling of chlorine, and carrying out a thermal reaction; (2) adding potassium fluoride into a reaction device containing methyl alcohol, methylbenzene and a solvent I, heating up and then stirring the mixture, and carrying out atmospheric distillation on reaction liquid to recover the methyl alcohol and the methylbenzene; after that, under the protection of nitrogen, adding the tetrachloro phthalylhydrazine prepared in the step (1) and a catalyst II into the product, heating up to 120-200 DEG C and carrying out a fluoridation reaction; (3) adding the tetrachloro phthalylhydrazine and sodium peroxide which are prepared in the step (2) into water, carrying out a hydrolysis reaction for 2-8 hours at the temperature of 10-50 DEG C, then adjusting the acidity of the obtained reaction liquid until the pH value of the reaction liquid is equal to 1-4, carrying out suction filtration and drying to obtain the tetrafluorophthalic acid.

Description

technical field [0001] The invention relates to a method for synthesizing organic compound 3,4,5,6-tetrafluorophthalic acid. Background technique [0002] 3,4,5,6-Tetrafluorophthalic acid, which has the molecular formula C 8 h 2 f 4 o 4 , whose structural formula is shown in S-1, and the pure product is a white granular crystalline solid. The compound is mainly used for pharmaceutical intermediates and intermediates for the synthesis of fluorine-containing aromatic chemicals. [0003] [0004] At present, the synthesis methods of 3,4,5,6-tetrafluorophthalic acid are as follows: [0005] 1. Using literature (Chemical Science and Technology Market, 2006 (07): 30-33), using tetrachlorophthalic anhydride as raw material, tetrafluorophthalic acid is obtained through imidization, fluorination, and sulfuric acid hydrolysis. Poor performance, many by-products, low yield, using sulfuric acid for hydrolysis reaction, the reaction time is about 15 to 40 hours, the production e...

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): C07C63/68C07C51/00
CPCC07C51/00C07D237/32C07C63/68
Inventor 钱超时云龙高锐陈新志
Owner ZHEJIANG UNIV
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