Method for preparing high-purity 4,4'-difluorobenzophenone

A difluorobenzophenone, high-purity technology, applied in the field of preparation of fluorine-containing intermediates, can solve the problems of difficult cost control, low yield, high temperature and pressure requirements, etc., and achieve broad application prospects and industrial value , raw materials are cheap and easy to obtain, and the synthetic process conditions are mild

Active Publication Date: 2015-05-13
RUYUAN YAO AUTONOMOUS COUNTY DONGYANGGUANG FORMED FOIL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, there are many routes for public reports on 4,4'-difluorobenzophenone, mainly as follows: (1) Patent EP 178184 reports that fluorobenzene and p-fluorobenzoyl chloride are used as raw materials in trichlorination Under the catalysis of aluminum, product is made, and this method yield is higher, and the purity of product is also relatively high, but the cost of the raw material p-fluorobenzoyl chloride of reaction is on the high side, is unfavorable for suitability for industrialized production; (2) China Pharmaceutical Industry Journal, 40(10), 737-738; 2009 Using fluorobenzene as raw material, the product was obtained under the direct catalysis of phosgene and aluminum trichloride, but the content of the isomer 2,4'-difluorobenzophenone in the product Higher, in addition phosgene is highly toxic, and the yield of this route is also low; (3) Journal of Hebei University of Science and Technology, 29 (1), 20-22; 2008 reported that fluorobenzene was used as raw material, carbon tetrachloride Under the catalysis of aluminum chloride, 4,4'-difluorodiphenyldichloromethane is generated, and then hydrolyzed under acidic conditions to obtain the product. This method is si

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Preparation of p-fluorobenzoic acid:

[0028] In a round-bottomed flask equipped with stirring, a thermometer, and a reflux condenser, add 220 g (2.0 mol) of p-fluorotoluene and 34 g (0.2 mol) of hydrobromic acid in sequence, and slowly raise the temperature to 75° C., then turn on the incandescent lamp to give Light source exposure. Start to add 680 g (6.0 mol) of 30% hydrogen peroxide dropwise, complete the dropwise addition within 3 hours, and keep the temperature for reaction for 6 hours. After the color of bromine in the reaction system basically faded, the conversion of p-fluorotoluene was completed by gas phase detection, cooled to room temperature, and the reaction product was poured into ice water, a large amount of white solids were precipitated, and about 266 g of p-fluorobenzoic acid was obtained after suction filtration. Yield 95.1%.

[0029] Preparation of p-fluorobenzoyl chloride:

[0030] Weigh 89.1g (0.3mol) of solid phosgene (BTC) and 63g (0.45mol) ...

Embodiment 2

[0034] Preparation of p-fluorobenzoic acid:

[0035] In a round-bottomed flask equipped with stirring, a thermometer, and a reflux condenser, add 220 g (2.0 mol) of p-fluorotoluene and 34 g (0.2 mol) of hydrobromic acid in sequence, and slowly raise the temperature to 100 ° C, then transfer the reaction to sunlight Next, let the sun shine under natural light. Start to drop 567 g (5.0 mol) of 30% hydrogen peroxide, and complete the dropwise addition within 3 hours, and keep the temperature for reaction for 6 hours. After the color of bromine in the reaction system basically faded, the conversion of p-fluorotoluene was completed by gas phase detection, cooled to room temperature, and the reaction product was poured into ice water, a large amount of white solids were precipitated, and about 261 g of p-fluorobenzoic acid was obtained after suction filtration. Yield 93.2%.

[0036] Preparation of p-fluorobenzoyl chloride:

[0037] Weigh 89.1g (0.3mol) of solid phosgene (BTC) and...

Embodiment 3

[0041] Preparation of p-fluorobenzoyl chloride:

[0042] In a round bottom flask equipped with stirring, a thermometer and a reflux condenser, add 220 g (2.0 mol) of p-fluorotoluene and 34 g (0.2 mol) of hydrobromic acid in sequence, and after slowly increasing the temperature to 50° C., turn on the ultraviolet lamp to give Irradiate with light source. Start to drop 1134 g (10.0 mol) of 30% hydrogen peroxide, and complete the dropwise addition within 3 hours, and keep the temperature for 6 hours. After the color of bromine in the reaction system basically faded, the conversion of p-fluorotoluene was completed by gas phase detection, cooled to room temperature, and the reaction product was poured into ice water, a large amount of white solids were precipitated, and about 269 g of p-fluorobenzoic acid was obtained after suction filtration. Yield 96.8%.

[0043] Preparation of p-fluorobenzoyl chloride:

[0044] Weigh 89.1g (0.3mol) of solid phosgene (BTC) and 105g (0.75mol) of...

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PUM

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Abstract

The invention discloses a method for preparing high-purity 4,4'-difluorobenzophenone. p-fluorotoluene is used as an initial raw material and oxidation reaction, chloroformylation reaction and condensation reaction are carried out, so that the target product 4,4'-difluorobenzophenone is finally obtained; the melting point of the product is 107-109 DEG C; the purity of the product is greater than or equal to 99.9 percent and accords with the purity requirement for synthesis of polyether-ether-ketone (PEEK). Moreover, according to the preparation method disclosed by the invention, the used raw material is cheap and is easy to obtain, the synthetic process conditions are mild and in the synthesizing process, a used reagent is relatively green and environmental-friendly, and thus, the method has wide application prospect and high industrial value.

Description

technical field [0001] The invention relates to the field of preparation of fluorine-containing intermediates, in particular to a method for preparing high-purity 4,4'-difluorobenzophenone. Background technique [0002] 4,4′-Difluorobenzophenone is an important fluorine-containing intermediate, which is an important intermediate for the synthesis of fluorine-containing drugs flunarizine, lomerizine, and almitrigine. Its special application lies in its It is the monomer of special high-performance engineering plastic polyetheretherketone (PEEK). In the chemical and military fields, polyetheretherketone (PEEK) is a special polymer material. It has physical and chemical properties such as high temperature resistance and chemical corrosion resistance. It is a kind of high temperature resistant structural material and electrical insulation material. It can be combined with glass fiber or carbon fiber to prepare reinforced materials. A class of polyarylether polymers obtained by ...

Claims

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Application Information

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IPC IPC(8): C07C49/813C07C45/45
CPCC07C45/46C07C51/60C07C49/813C07C63/70
Inventor 李凯伍阳王发平方海亮曾水明刘新烁
Owner RUYUAN YAO AUTONOMOUS COUNTY DONGYANGGUANG FORMED FOIL CO LTD
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