Method for synthesis of 2'-fluoro terphenyl liquid crystal

A technology of terphenyls and liquid crystals, which is applied in the direction of liquid crystal materials, organic chemical methods, chemical instruments and methods, etc., can solve the problems of expensive catalysts, cumbersome synthesis, environmental hazards, etc., and achieve low cost, high yield and purity, and reduce pollution effect

Inactive Publication Date: 2012-04-04
SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved in the present invention is to provide a simple, efficient and environment-friendly method for preparing liquid crystals containing 2′-fluoroterphenyls. The catalysts used in the prior art are cumbersome to synthesize, have low yields, and are seriously harmful to the environment. Expensive or harmful to the human body, it can reduce production costs, reduce environmental pollution, and can meet the needs of industrial synthesis of monomeric liquid crystals containing terphenyl

Method used

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  • Method for synthesis of 2'-fluoro terphenyl liquid crystal
  • Method for synthesis of 2'-fluoro terphenyl liquid crystal
  • Method for synthesis of 2'-fluoro terphenyl liquid crystal

Examples

Experimental program
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Embodiment 1

[0035] In this example, the intermediate 4'-propyl-3-fluoro-4-bromobiphenyl is reacted with 4-bromo-3-fluoroiodobenzene and propylphenylboronic acid to obtain 4-ethyl- Taking 2'-fluoro-4"-propyl (1,1',4',1") terphenyl as an example, the synthesis method of the present invention will be further described.

[0036] Step 1, the synthesis of 4'-propyl-3-fluoro-4-bromobiphenyl

[0037] Add 150.5g (0.5mol) of 4-bromo-3-fluoroiodobenzene, 138g of potassium carbonate, 86.1g (0.525mol) of propylphenylboronic acid, and 3g (0.0026mol) of tetrakis(triphenylphosphine) palladium into the three-necked flask , and added 300 g of toluene, 210 g of ethanol, and 240 g of water; then stirred evenly and heated to 70°C, keeping the temperature at 70-75°C for 6 hours. After the solution has dropped to room temperature, carry out liquid separation treatment, wash the organic phase with water until it is neutral, and distill off the toluene, collect the fraction at 150°C / 20Mpa under reduced pressure ...

Embodiment 2

[0054] Step 1, the synthesis of 4'-ethyl-3-fluoro-4-bromobiphenyl

[0055] Add 150.5g (0.5mol) of 4-bromo-3-fluoroiodobenzene, 138g of potassium carbonate, 78.8g (0.0525mol) of ethyl phenylboronic acid, 3.5g (0.003mol) of tetrakis(triphenylphosphine) palladium into the three-necked flask respectively. ), and added 300g of toluene, 210g of ethanol, and 240g of water; then stirred evenly and heated to 70°C, keeping the temperature at 70-75°C for 6 hours. After the solution was cooled to room temperature, liquid separation was performed, the organic phase was washed with water until neutral, and the toluene was evaporated, and the fraction at 145°C / 20Mp was collected under reduced pressure to obtain 4'-ethyl-3-fluoro-4-bromobi Benzene 103.2g, the yield is 74%. The gas chromatographic purity GC was analyzed to be 99%.

[0056] Step 2, Synthesis of 4-propyl-2'-fluoro-4"-ethyl (1,1',4',1") terphenyl

[0057]

[0058] 83.7g (0.3mol) 4'-ethyl-3-fluoro-4-bromobiphenyl, 54.1g (0.3...

Embodiment 3

[0073] Step 1, Synthesis of 4'-pentyl-3-fluoro-4-bromobiphenyl

[0074] The difference between this step of this example and step one of Example 1 is that the first phenylboronic acid is pentylphenylboronic acid, and the addition amount is 100.8g (0.525mol); in this way, 4′-pentyl-3-fluoro-4 - 115.6 g of brominated biphenyls, the yield is 72%.

[0075] The gas chromatographic purity GC was analyzed to be 99%.

[0076] Step 2, 4-ethyl-2'-fluoro-4"-pentyl (1,1',4',1") terphenyl

[0077]

[0078] 96.3g (0.3mol) 4'-pentyl-3-fluoro-4-bromobiphenyl, 49.5g (0.33mol) p-ethylphenylboronic acid, 5% Pd / C 1.5g (0.0007mol), potassium carbonate 83g , 750g of tetrahydrofuran, and 200g of water were added to a three-necked flask, heated to 70°C, refluxed for 15 hours, cooled and added with 500ml of toluene, separated, washed with water until neutral, and evaporated to clean the toluene. The product was purified by column chromatography, and recrystallized twice with 2 times of ethanol a...

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Abstract

The present invention discloses a method for synthesis of 2'-fluoro terphenyl liquid crystal. With the present invention, problems of more reaction steps, low yield, heavy environmental hazard, expensive catalysts, or hazard on the human body in the prior art are solved. The technical scheme of the present invention is that: a catalyst is added to an organic solvent of the raw material to carry out a suzuki coupling reaction to realize the synthesis of the 2'-fluoro terphenyl liquid crystal. According to the present invention, 4-bromo-3-fluoro iodobenzene, a phenyl boronic acid derivative and a base are adopted as raw materials, and are subjected to two suzuki coupling reactions in the solvent under the effect of the catalyst at the reaction temperature of 70-100 DEG C to obtain the 2'-fluoro terphenyl liquid crystal, wherein the times of the two suzuki coupling reactions are respectively 4-10 hours and 10-20 hours. The method of the present invention has advantages of simple process, mild conditions, low preparation cost, high yield, environmental protection, and strong practicability.

Description

technical field [0001] The invention belongs to the field of chemical industry, and relates to a method for synthesizing liquid crystal intermediates and monomer liquid crystals in electronic materials, in particular to a method for preparing liquid crystals containing 2'-fluorine terphenyls by means of Suzuki coupling reaction. Background technique [0002] Fluorine-containing terphenyl monomeric liquid crystals generally have low melting point, high clearing point and low viscosity, and have good compatibility with other monomeric liquid crystals, so there are a large number of STN liquid crystal displays and TFT liquid crystal displays. Applications. The method for preparing fluorine-containing terphenyl monomer liquid crystals in the prior art includes the synthetic method of the disclosed fluorine-containing terphenyl monomer liquid crystals in US4696549, which was published in 1987 by the method of Merck Company. Its shortcoming is that there are many reaction steps, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07B37/00C07C17/263C07C25/18C09K19/12C09K19/30
Inventor 韩耀华丁兴立钤秀丽赵立峰李红利柳仁杰梁志安张建立
Owner SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
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