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Preparation method of biphenyl liquid crystal compound

A technology of liquid crystal compounds and biphenyls, which is applied in the field of preparation of liquid crystal compounds, can solve the problems of low yield, cumbersome reaction steps, environmental pollution, etc., achieve good purity, reduce reaction steps, and increase yield

Active Publication Date: 2015-04-22
烟台海川化学制品有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although biphenyl compounds were synthesized, the yield was very low
[0004] Document 2 The synthesis of biphenyl fluorine-containing liquid crystals by Suzuki coupling reaction catalyzed by palladium diphenylphosphine acetate (Applied Chemistry, No. 5, 2007, Page: 489-493) also involves the preparation of this biphenyl compound. The use of bromine simple substance causes pollution to the environment
Simultaneously reaction step is more loaded down with trivial details, yield is lower

Method used

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  • Preparation method of biphenyl liquid crystal compound
  • Preparation method of biphenyl liquid crystal compound
  • Preparation method of biphenyl liquid crystal compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] The specific process steps for preparing biphenyl liquid crystal compound (trans, trans) 4'-(4'-ethylbicyclohexyl)-3,4-difluorobiphenyl (CCB2FF):

[0057] 1. Preparation of 4-[4-(4'-ethylcyclohexyl)-1-cyclohexenyl]-bromobenzene

[0058] 1. Preparation of 4-(4'-ethylbicyclohexyl)-1'-hydroxyl-bromobenzene

[0059]The 2L three-necked bottle is equipped with stirring, liquid seal, thermometer and sleeve, constant pressure dropping funnel and drying tube. Add 23gMg (0.96mol) and 200ml THF to the three-necked flask, start stirring at about 40-60rpm, then add 2 grains of iodine and 2ml of bromoethane to initiate the reaction. A solution prepared by 226.6g (0.96mol) p-dibromobenzene and 600g THF was added dropwise at room temperature, and kept at 45-60°C for 2 hours.

[0060] After the heat preservation is completed, a mixed solution of 166.4g (0.8mol) 2HHK and 400ml THF is added dropwise at a temperature controlled below 60°C. After the dropwise addition, the reaction was i...

Embodiment 2

[0074] Preparation of biphenyl liquid crystal compound 4'-[trans-4-[2-(trans-4-propylcyclohexyl)ethyl]cyclohexyl]-3,4-difluoro-1,1'-biphenyl (3H2HPGF ) specific process steps:

[0075] 1. Preparation of 4-[4-[2-(4-propylcyclohexyl)ethyl]cyclohexenyl]bromobenzene

[0076] 1. Preparation of 4-[4-[2-(4-propylcyclohexyl)ethyl]cyclohexyl, 1-hydroxyl]bromobenzene

[0077] The 2L three-necked bottle is equipped with stirring, liquid seal, thermometer and sleeve, constant pressure dropping funnel and drying tube. Add 23g (0.96mol) Mg and 200ml THF to the three-neck flask, then add 2 grains of iodine and 2ml of bromoethane. Turn on the stirring at about 40-60rpm to initiate the reaction. 226.6g (0.96mol) p-dibromobenzene and 600g THF were added dropwise at room temperature, and kept at 45-60°C for 2 hours.

[0078] After the heat preservation was completed, a solution of 200g (0.8mol) ECCH3K and 300g THF was added dropwise at a temperature controlled below 60°C. After the dropwise...

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Abstract

The invention relates to a preparation method of a liquid crystal compound and especially relates to a preparation method of a biphenyl liquid crystal compound. The preparation method comprises the following steps that a Grignard reagent produced by a reaction of p-dibromobenzene and magnesium powder undergoes a reaction with para-substituted cyclohexyl ketone; an aromatic halide prepared by the previous step and substituted phenylboronic acid undergo a SUZUKI reaction in the presence of a catalyst; the product obtained by the previous step undergoes a reduction reaction in the presence of Pd / C as a catalyst to produce a trans-and cis- mixed biphenyl compound; and the trans-and cis- mixed biphenyl compound is transformed into a trans-biphenyl compound which is the biphenyl liquid crystal compound. The preparation method of the biphenyl liquid crystal compound utilizes dibromobenzene to replace bromobenzene so that reaction processes are reduced; the use of elementary bromine is avoided; a reaction yield is greatly improved; high product purity is realized; green chemistry requirements are satisfied; and large-scale industrial production can be realized.

Description

technical field [0001] The present invention relates to a method for preparing a liquid crystal compound, in particular to a method for preparing a biphenyl liquid crystal compound. Background technique [0002] Biphenyl liquid crystals have been widely used in the production of liquid crystals, but there are still great defects in the preparation of biphenyl liquid crystals. [0003] Patent 1EP0291949A2 introduces the preparation of similar substances, the method involved is Grignard reagent and iodide in PdCl 2 Catalyzed coupling. Although biphenyl compounds were synthesized, the yield was very low. [0004] Document 2 The synthesis of biphenyl fluorine-containing liquid crystals by Suzuki coupling reaction catalyzed by palladium diphenylphosphine acetate (Applied Chemistry, No. 5, 2007, Page: 489-493) also involves the preparation of this biphenyl compound. The use of bromine simple substance will pollute the environment. Simultaneously, the reaction steps are more lo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C25/18C07C17/358C07C17/354C09K19/30
Inventor 袁鹄周鹏王玉昌王志勇朱政竹姜亚楠
Owner 烟台海川化学制品有限公司