Method for preparing trifluoromethyl-benzene-containing liquid crystals

A technology of trifluoromethylation and alkylation, applied in the field of catalytic synthesis, can solve problems such as low yield, and achieve the effects of improving yield and product quality, improving yield and simple method

Active Publication Date: 2012-09-19
SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] It has been verified by experiments that the yields of these two methods are very low, the yield of the first method is 0%, and the yield of the second method is 15%.

Method used

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  • Method for preparing trifluoromethyl-benzene-containing liquid crystals
  • Method for preparing trifluoromethyl-benzene-containing liquid crystals
  • Method for preparing trifluoromethyl-benzene-containing liquid crystals

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Example 1 Preparation of propylcyclohexylphenyl o-fluorotrifluoromethylbenzene

[0040]

[0041] Add 50.6g (0.12mol) iodopropylcyclohexyl m-fluorobiphenyl (reactant), 45.7g (0.24mol) (catalyst) of cuprous iodide, 45.6g (0.3mol) trifluoroacetic acid in a 1L three-necked flask Potassium (reactant), 506g N.N dimethylformamide (solvent), heated to 150°C for 5 hours, evaporated 400ml N.N dimethylformamide under reduced pressure, added 300ml toluene (solvent), poured out the supernatant, Add 200ml of water to the lower solid to filter out cuprous iodide, combine the filtrate and supernatant, separate the lower aqueous phase and extract it with 100ml×2 toluene, combine the organic phase, wash with 200ml×3 water, evaporate toluene to dryness, and detect the product in the reaction solution The content is 95.4%. The product is decolorized by silica gel column chromatography, and recrystallized three times with 3 times of petroleum ether and 0.5 times of ethanol to obtain the ...

Embodiment 2

[0046] Example 2 Preparation of propylcyclohexylphenyl-2,6-difluoro-4-trifluoromethylbenzene

[0047]

[0048] In a 2L three-necked flask, add propylcyclohexylphenyl-2,6-difluoroiodobenzene (reactant) 66g (0.15mol) potassium trifluoroacetate (reactant) 57g (0.375mol), cuprous iodide (catalyst) ) 57g (0.3mol), N.N dimethylformamide (solvent) 660g, heated to 150°C for 5 hours, distilled off 400ml of solvent, cooled to 80°C, added 500ml of toluene (solvent), 500ml of water, stirred for 20 minutes, The solid was filtered out, the filtrate was separated, the water was extracted, and the toluene was evaporated to dryness. The detected content of the reaction solution was 93% propylcyclohexylphenyl-2,6-difluoro-4-trifluoromethylbenzene, and the silica gel chromatography column Decolorize and recrystallize with 1.5 times of petroleum ether and 1 times of ethanol to obtain 28.5 g of the target compound with a yield of 60%. The experimental results are as follows:

[0049] (1) Gas ...

Embodiment 3

[0053] Example 3 Preparation of pentylcyclohexylphenyl o-fluorotrifluoromethylbenzene

[0054] Referring to Example 1 in this example, the reaction raw material in Example 1 was replaced with iodopropylcyclohexyl-m-fluorobiphenyl to prepare the following compounds with a yield of 60%;

[0055]

[0056] (1) GC-MS data analysis: 392 (M+46.4) 373 (6.2) 279 (27.8) 266 (100) 253 (58.7) 196 (13.4) 183 (14.4);

[0057] (2) DSC analysis, mp: 66.17-70.39°C.

[0058] As can be seen from the above, the product has a correct structure and is the target compound shown in Formula I.

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Abstract

The invention discloses a method for preparing trifluoromethyl-benzene-containing liquid crystals, which comprises the following steps: evenly mixing a compound disclosed as Formula II and a trifluoromethylating reagent to carry out catalytic reaction, and obtaining a compound disclosed as Formula I after the reaction finishes. Compared with other methods, the method disclosed by the invention uses potassium trifluoroacetate as the trifluoromethylating reagent instead of sodium trifluoroacetate, thereby greatly enhancing the yield. The method has the advantage of accessible raw materials, is simple, is especially suitable for synthesizing high-dielectric-anisotropy liquid crystal compound monomers, and can effectively enhance the reaction yield and the product quality. Formula I and formula II are shown in the description.

Description

technical field [0001] The invention belongs to the technical field of catalytic synthesis of monomeric liquid crystals in electronic materials, and relates to a method for preparing monomeric liquid crystals containing trifluoromethylbenzene. Background technique [0002] Liquid crystal materials are rapidly developing with the development of liquid crystal displays. According to the operation mode of liquid crystals, liquid crystal display devices can be divided into TN type (twisted nematic phase), STN type (super twisted nematic phase), TFT (thin film transistor) Type, PDLC (Polymer Dispersed Liquid Crystal) type display device. [0003] Liquid crystal display devices are closely related to the properties of liquid crystal materials, as shown in the table below. [0004] Numbering Properties of Mixed Liquid Crystals Display Characteristics 1 Wide temperature range of nematic phase Wide temperature range available 2 Appropr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C25/18C07C17/32C09K19/30
Inventor 韩耀华丁兴立赵立峰张建立华瑞茂
Owner SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
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