The preparation method of 4,5-difluorophthalic acid

A technology of difluorophthalic acid and phthalic acid, which is applied in the field of compound preparation, can solve problems such as difficulty in obtaining raw materials, and achieve the effects of low cost of raw materials, easy industrial production, and safe, efficient and easy-to-operate process.

Active Publication Date: 2022-06-07
苏州当量生物医药有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] For the above synthetic route, there is a dangerous process of high temperature and high pressure or the target product is finally obtained through multi-step complex reactions, and all of them use 4,5-dichlorophthalic acid as a raw material, which is not easy to obtain, so a new one is developed Synthetic route is the technical problem to be solved in this application

Method used

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  • The preparation method of 4,5-difluorophthalic acid
  • The preparation method of 4,5-difluorophthalic acid
  • The preparation method of 4,5-difluorophthalic acid

Examples

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Embodiment 1

[0027] Synthesis of 4,5-difluoro-1,2-phthalonitrile: add 271.8g of 1,2-dibromo-4,5-difluorobenzene and 27g of polymethylpolysiloxane to a 3000mL reaction flask , stirred with 1450 mL of N,N-dimethylacetamide (DMAC) to dissolve, and after three nitrogen replacements, heated to 100 °C for 1 h. Turn off the heating, add 16.3 g of tris(dibenzylideneacetone)dipalladium (Pd 2 (dba) 3 ) and 12.3g of 1,1'-bis(diphenylphosphino)ferrocene (dppf), then slowly added 120g of zinc cyanide, reacted at 100°C for 16 hours, and monitored the reaction by thin layer chromatography (TLC). After the reaction of the raw materials was completed, the reaction was stopped and the temperature was lowered. The reaction solution was poured into 7 L of water, and 2 mol / L of sodium bicarbonate solution was slowly added under vigorous stirring to adjust the pH to about 8. Fully stirred for 3 hours, filtered, the filter cake was rinsed with ethyl acetate until there was no coloration, the filtrate was extra...

Embodiment 2

[0030] Synthesis of 4,5-difluoro-1,2-phthalonitrile: add 271.8g of 1,2-dibromo-4,5-difluorobenzene and 33.8g of polymethyl polysiloxane to a 3000mL reaction flask alkane, dissolved with 1800 mL of DMAC by stirring, replaced with nitrogen three times, heated to 100 °C, and reacted for 1 h. Turn off the heat and add 18g of Pd 2 (dba) 3 and 14.5g of dppf, slowly add 120g of zinc cyanide, react at 120°C for 10 hours, monitor the reaction by thin layer chromatography (TLC), stop the reaction after the reaction of the raw materials and cool down, pour the reaction solution into 7L of water, stir vigorously Then slowly add 2mol / L sodium bicarbonate solution to adjust the pH to about 8. Stir well for 3 hours and filter. The filter cake was rinsed with ethyl acetate until there were no spots and no color was developed, the filtrate was extracted with ethyl acetate, the combined organic phases were backwashed twice with saturated brine, and dried over anhydrous sodium sulfate. The o...

Embodiment 3

[0033] Synthesis of 4,5-difluoro-1,2-phthalonitrile: add 271.8g of 1,2-dibromo-4,5-difluorobenzene and 33.8g of polymethyl polysiloxane to a 3000mL reaction flask alkane, dissolved in 1000 mL of DMAC with stirring, replaced with nitrogen three times, heated to 100 °C, and reacted for 1 h. Turn off the heat and add 16.3 g of Pd 2 (dba) 3 and 12.3g of dppf, slowly add 120g of zinc cyanide, react at 100°C for 10 hours, monitor the reaction by thin layer chromatography (TLC), stop the reaction after the reaction of the raw materials and cool down, pour the reaction solution into 7L of water, stir vigorously Then slowly add 2mol / L sodium bicarbonate solution to adjust the pH to about 8. Stir well for 3 hours and filter. The filter cake was rinsed with ethyl acetate until there were no spots and no color was developed, the filtrate was extracted with ethyl acetate, the combined organic phases were backwashed twice with saturated brine, and dried over anhydrous sodium sulfate. Th...

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Abstract

The invention discloses a preparation method of 4,5-difluorophthalic acid, the specific method steps are as follows: S1: Synthesis of 4,5-difluoro-1,2-phthalonitrile: add 4,5 ‑Difluoro‑1,2‑dihalobenzene and polymethylhydrogensiloxane, stirred and dissolved with N,N‑dimethylacetamide, and reacted, cooled after the reaction, and added tri( Dibenzylideneacetone) dipalladium and 1,1'-bis(diphenylphosphino)ferrocene, then slowly add zinc cyanide for reaction, after the reaction is completed, cool down and add water, and use sodium bicarbonate solution under vigorous stirring Adjust the pH to 8, stir for 2 hours and then filter, wash and elute with a mixed solvent of petroleum ether and ethyl acetate to obtain an off-white solid intermediate 4,5-difluoro-1,2-phthalonitrile; S2: Synthesis of 4,5‑difluoro‑1,2‑phthalic acid. The process of the invention is safe, efficient and easy to operate, has low requirements on equipment, low cost of raw materials, and is easy for industrialized production.

Description

technical field [0001] The invention relates to the technical field of compound preparation, in particular to a preparation method of 4,5-difluorophthalic acid. Background technique [0002] 4,5-Difluorophthalic acid and its derivatives are currently one of the important chemical raw materials in the field of organic optoelectronic materials, especially OPV (organic photovoltaic solar cells). Among the existing technologies: [0003] G. Denanteuil et al. used 4,5-dichlorophthalic anhydride and potassium fluoride as raw materials, and sulfolane as solvent. After reacting at 180 degrees in an autoclave for 24 hours, they were cooled, washed with alkali, and acidified to obtain The target 4,5-difluorophthalic acid. [0004] [0005] The Chinese patent with publication number CN104530058B uses 4,5-dichlorophthalic acid as a raw material, and is dehydrated by acetic anhydride to obtain 4,5-dichlorophthalic anhydride (Intermediate 1); Intermediate 1 uses acetic acid as a solv...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C51/08C07C63/68C07C253/14C07C253/34C07C255/51
CPCC07C51/08C07C253/14C07C253/34C07C255/51C07C63/68Y02E10/549Y02P70/50
Inventor 高伟孔正环其他发明人请求不公开姓名
Owner 苏州当量生物医药有限公司
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