Method for preparing difluoromethoxy bridge type liquid crystal

A compound and selected technology, applied in liquid crystal materials, chemical instruments and methods, preparation of organic compounds, etc., can solve the problems of low total yield, unfavorable, cost reduction, etc., and achieve the improvement of total reaction yield and reduction of reaction steps , Simplify the effect of reaction intermediates

Inactive 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

[0008] It has been verified by experiments that the total yield of these two methods is very low due to the sequential synthesis of the molecular structure of the compound from left to right. The total yield of the compound obtained by using the two methods is only 20%, and the terminal alkyl It is necessary to re-synthesize, which is not conducive to comprehensive cost reduction

Method used

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  • Method for preparing difluoromethoxy bridge type liquid crystal
  • Method for preparing difluoromethoxy bridge type liquid crystal
  • Method for preparing difluoromethoxy bridge type liquid crystal

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Embodiment 1, the preparation of 4-(difluoro(3,4,5-trifluorophenoxy)methyl)-3,5-difluoro-4'-propylbiphenyl

[0035]

[0036] Add 38.9g (0.1mol) of compound 5-bromo-2-(difluoro(3,4,5-trifluorophenoxy)methyl)-1,3-difluorobenzene shown in formula II to a 250mL three-necked flask 18g (0.11mol) of compound propylphenylboronic acid shown in formula III, 32.1g (0.275mol) anhydrous sodium carbonate, 50ml toluene, 25ml ethanol, 25ml water, 1.15g (0.001mol) tetrakis triphenyl phosphide palladium, React at 90°C for 6 hours, add 100ml of toluene and 100ml of water, separate the lower aqueous phase and extract with 100ml×2 toluene, combine the organic phases, wash with 200ml×3 saturated saline, evaporate toluene to dryness, decolorize the product with silica gel column chromatography, and use 3 times of ethanol and 0.5 times of petroleum ether were recrystallized twice to obtain the target compound with a yield of 65%.

[0037] The experimental results are as follows:

[0038] ...

Embodiment 2

[0042] Example 2, 2-(4'-(difluoro(3,4,5-trifluorophenoxy)methyl)-3',5'-difluorobiphenyl)-5-propyltetrahydropyran preparation of

[0043]

[0044] Add 43.6g (0.1mol) compound 5-iodo-2-(difluoro(3,4,5-trifluorophenoxy)methyl)-1,3-difluorobenzene shown in formula II to a 1L three-necked flask 27.3g (0.11mol) of compound 4-(5-propyl tetrahydropyran-2-) phenylboronic acid shown in formula III, 32.1g (0.275mol) anhydrous sodium carbonate, 500ml toluene, 25ml ethanol, 25ml water, 1.25g (0.001mol) tetrakistriphenylphosphine palladium, react at 90°C for 6 hours, add 100ml toluene, 100ml water, separate the lower aqueous phase and extract it with 100ml×2 toluene, combine the organic phases, and use 200ml×3 saturated saline Wash with water, evaporate toluene to dryness, decolorize the product by silica gel column chromatography, and recrystallize twice with 3 times ethanol and 0.5 times petroleum ether to obtain the target compound with a yield of 70%.

[0045] The experimental resu...

Embodiment 3

[0050] Example 3, 2-(4'-(difluoro(3,4,5-trifluorophenoxy)methyl)-2,3',5',6-tetrafluorobiphenyl)-5-propyl Preparation of Tetrahydropyran

[0051] With reference to Example 1 in this embodiment, the reaction raw material propylphenylboronic acid in Example 1 was replaced by 2,6-difluoro-4-(5-propyltetrahydropyran 2-)phenylboronic acid to prepare the following compounds, The yield is 72%;

[0052]

[0053] (1) GC: 99.9%;

[0054] (2) GC-MS data analysis: 548 (M+0.4) 417 (100) 336 (27.8) 131 (14.4);

[0055] (3) mp: 83°C, Δε: 35.6, Δn: 0.1316, γ: 457.

[0056] It can be known from the above that the compound has a correct structure and is a compound shown in formula I.

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Abstract

The invention discloses a method for preparing a difluoromethoxy bridge type liquid crystal compound, which comprises the following steps: uniformly mixing a compound shown in a formula II and a compound shown in a formula III with alkali under the condition that a catalyst exists for reaction and obtaining a compound shown in a formula I after reaction. The method has the beneficial effects that a reaction substrate is changed into the compound shown in the formula II and a phenylo boric acid derivative shown in the formula III, the reaction steps are reduced, a reaction intermediate is simplified, the total reaction yield is greatly improved, and different group compounds can use the same intermediate formula I. The method is particularly suitable for preparing the difluoromethoxy bridge type liquid crystal compound. Formula II, formula III and formula I are shown in the instruction.

Description

technical field [0001] The invention belongs to the technical field of synthesis of monomeric liquid crystals in electronic materials, and relates to a method for preparing monomeric liquid crystals containing difluoromethoxy bridges. Background technique [0002] With the rapid development of liquid crystal display technology, TFT-LCD has become the mainstream of liquid crystal display, but the problems of animation afterimage and tailing in video are still unsolved. The main reason for this phenomenon is the slow response speed of liquid crystal. The viscosity of the liquid crystal material directly determines the response speed of the liquid crystal display. Traditional ester liquid crystals and cyano-containing liquid crystals are limited in TFT liquid crystal display applications due to their low resistivity and low voltage retention. A large number of studies have shown that fluorine-containing liquid crystal is the most suitable material for TFT liquid crystal displa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C43/225C07C41/30C07D309/06C07D407/04C09K19/20C09K19/34C09K19/32C09K19/30
Inventor 张兴华瑞茂李宁周兴丹李正强
Owner SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
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