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Preparation method of trienes liquid crystal monomers

A technology of liquid crystal monomers and olefins, applied in the field of preparation of triene liquid crystal monomers, can solve the problems of unfavorable industrial production and low product yield

Active Publication Date: 2015-08-19
VALIANT CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The technical problem to be solved by the present invention is to provide a method for preparing a triene liquid crystal monomer compound, which is used to prepare a triene liquid crystal monomer compound for liquid crystal display. The method is simple, efficient, and has a high yield. There are problems such as low product yield in the technology, which is not conducive to industrial production, and meets the requirements of mass industrialization of such products

Method used

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  • Preparation method of trienes liquid crystal monomers
  • Preparation method of trienes liquid crystal monomers
  • Preparation method of trienes liquid crystal monomers

Examples

Experimental program
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Effect test

Embodiment 1

[0061] Example 1 Preparation of 1-ethoxy-2,3-difluoro-4-{4-[2-(4-vinyl-cyclohexyl)-vinyl]-cyclohex-1-enyl}-benzene

[0062] 1) 4-(4-ethoxy-2,3-difluoro-phenyl)-4-hydroxy-cyclohexanone ethylene acetal Put 99.5g (0.63mol) of 1-ethoxy-2,3-difluorobenzene and 600g of THF into a 2L three-necked flask, stir and cool the system down to -60°C, and dropwise add 286mL (0.63mol) of n-butyllithium n-hexane solution, keep warm at -60°C for 2h, add dropwise a solution of 93.6g (0.6mol) KCR and 150g THF, keep warm at -60°C for 1h, hydrolyze and separate layers, wash the organic phase with water until pH = 7, do not do any treatment, and wait for the next step Reaction, product GC purity 96.2%.

[0063] 2) 4-(4-ethoxy-2,3-difluoro-phenyl)-4-hydroxy-cyclohexanone In the 2L there-necked flask, drop into the solution of 4-(4-ethoxy-2,3-difluoro-phenyl)-4-hydroxyl-cyclohexanone ethylene ketal obtained in the previous step, 324g of formic acid with a mass fraction of 85% , 60 ℃ heat preservat...

Embodiment 2

[0070] Preparation of 1-butoxy-2,3-difluoro-4-{4-[2-(4-vinyl-cyclohexyl)-vinyl]-cyclohex-1-enyl}-benzene

[0071] 1) 4-(4-Butoxy-2,3-difluoro-phenyl)-4-hydroxy-cyclohexanone ethylene acetal Put 15.1g (0.63mol) of magnesium bars into a 2L three-necked flask, add dropwise a solution of 158.4g (0.63mol) of 1-bromo-4-butoxy-2,3-difluorobenzene and 500g of THF at 25°C, and react 2 After 1 hour, a solution of 93.6g (0.6mol) KCR and 150g toluene was added dropwise, kept at 25°C for 1h, hydrolyzed and separated, and the organic phase was washed with water until pH = 7, then left untreated and waited for the next reaction. The GC purity of the product was 93.8%.

[0072] 2) 4-(4-butoxy-2,3-difluoro-phenyl)-4-hydroxy-cyclohexanone Put the solution of 4-(4-butoxyl-2,3-difluoro-phenyl)-4-hydroxyl-cyclohexanone ethylene ketal obtained in the previous step into a 2L three-necked flask, 268.2g of 85% mass fraction Formic acid, heat preservation reaction at 70°C for 2 hours; after heat pr...

Embodiment 3

[0079] Preparation of 1-ethyl-2,3-difluoro-4-{4-[2-(4-propenyl-cyclohexyl)-vinyl]-cyclohex-1-enyl}-benzene

[0080] 1) 4-(4-Ethyl-2,3-difluoro-phenyl)-4-hydroxy-cyclohexanone ethylene acetal Put 89.5g (0.63mol) of 1-ethyl-2,3-difluorobenzene and 400g THF into a 2L three-necked flask, stir and cool the system down to -40°C, add 0.63mol of sec-butyl lithium in n-hexane dropwise, Incubate at -40°C for 2 hours, add dropwise a solution of 93.6g (0.6mol) KCR and 150g THF, incubate at -40°C for 1h, hydrolyze and separate layers, wash the organic phase with water until pH = 7, leave it alone, wait for the next reaction, the product GC 97.1% purity.

[0081] 2) 4-(4-Ethyl-2,3-difluoro-phenyl)-4-hydroxy-cyclohexanone In the 2L there-necked flask, drop into the solution of 4-(4-ethyl-2,3-difluoro-phenyl)-4-hydroxyl-cyclohexanone ethylene ketal obtained in the previous step, 381g of formic acid with a mass fraction of 85%, Insulate and react at 60°C for 3 hours; complete the incubati...

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Abstract

The invention relates to a preparation method of trienes liquid crystal monomers. The method comprises the following steps: using alkyl 2,3-difluorobenzene, alkoxy 2,3-difluorobenzene, 1-bromine-4-alkyl 2,3-difluorobenzene or 1-bromine-4-alkoxy 2, 3-difluorobenzene as raw materials, performing a metallization reaction or a Grignard reaction and a reaction with a cyclohexanone compound, performing hydroxyl protection, a Wittig reaction, alkene-ether hydrolysis, hydroxyl deprotection and alcohol dehydration so as to obtain an intermediate of which the formula is shown in the specification, performing the Wittig reaction once again, and performing a double-bond isomerization reaction so as to obtain the finished product, wherein three steps of the reactions of the alkene-ether hydrolysis, the hydroxyl deprotection and the alcohol dehydration can be combined to be performed in one step. The preparation method disclosed by the invention overcomes the disadvantage that the yield of cyclohexenone in the Wittig reaction is extremely low in the conventional preparation method of the compound, the yield of products is increased, the production cost is reduced, the large-scale production is facilitated, and the preparation method has very good application prospects.

Description

technical field [0001] The invention relates to a preparation method of a triene liquid crystal monomer, belonging to the field of liquid crystal displays. Background technique [0002] In recent years, liquid crystals with negative dielectric anisotropy have become more and more widely used. Vinyl compounds are important groups of this type of liquid crystal compounds. Liquid crystal compounds containing this group have the characteristics of low viscosity, high charge retention rate, and superior performance. . Some of these compounds can be represented by the following structural formula: [0003] [0004] The Ra is C 1 ~C 10 straight-chain alkyl or alkoxy, Rb is hydrogen or C 1 ~C 4 straight-chain alkyl groups. [0005] At present, the preparation of such compounds mainly relies on the following methods, in which intermediates The α-hydrogen of the ketone in the structure is easy to be removed under alkaline conditions to form a stable conjugated enol structur...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C43/225C07C41/32C07C25/18C07C17/358C09K19/30
CPCC07C17/358C07C25/18C07C41/32C07C43/225C07C2601/14C07C2601/16C09K19/3098
Inventor 付海超周银波万君玲刘忠文陈帅于琳
Owner VALIANT CO LTD
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