Benzene nitrile monomer liquid crystal preparation method

A technology of benzonitriles and monomers, which is applied in the field of monomer liquid crystal preparation, can solve the problems of environmental pollution damage, high cost of raw materials, waste acid discharge, etc., and achieve the effects of being environmentally friendly, reducing reaction steps, and reducing pollution

Active Publication Date: 2007-05-23
VALIANT CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The disadvantage is that the cost of raw materials used in the iodination reaction is high, the yield is very low, and a large amount of waste acid is discharged, causing pollution and damage to the environment

Method used

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  • Benzene nitrile monomer liquid crystal preparation method
  • Benzene nitrile monomer liquid crystal preparation method
  • Benzene nitrile monomer liquid crystal preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] 1.1: Raw material 4-(trans-4'-propylcyclohexyl)-2,6-difluorochlorobenzene [structural formula: preparation of

[0028] Add 12.2g (0.5mol) of magnesium chips into a 1L three-necked flask, 113.7g (0.5mol) of 2,6-difluoro-4-bromochlorobenzene is miscible in 300ml of tetrahydrofuran, drop a little into the three-necked flask, and heat up to 70°C, the reaction was initiated, and the remaining 2,6-difluoro-4-bromochlorobenzene solution was added dropwise. After the addition was completed, the mixture was kept at reflux for 1 hour. Dissolve 70.0g (0.5mol) of p-propylcyclohexanone in 100ml of tetrahydrofuran, drop it into the Grignard reagent obtained from the above reaction, after the addition is complete, keep it warm for 1 hour, then add dilute hydrochloric acid for hydrolysis, and extract it three times with 100ml of toluene , combine the organic phases, wash with water until neutral, add 8.6g (0.05mol) of p-toluenesulfonic acid into the above-mentioned toluene solution, ...

Embodiment 2

[0036] 2.1: Raw material 4-〖trans-4′-[2″-(trans-4-propylcyclohexyl)ethylene]cyclohexyl〗2-fluorochlorobenzene, [structural formula: ] Preparation:

[0037] With 123g (0.5mol) of and 104.7g (0.5mol) Grignard reagent reaction, prepared Then use 8.6g (0.05mol) of p-toluenesulfonic acid to dehydrate to obtain Double bond hydrogenation with Raney Ni yielded 170 g of mixed cis and trans GC: 95%, then use 58.7g (0.44mol) of aluminum trichloride, 72g sherwood oil < 5 ℃ condition conversion, then recrystallize three times with the mixed solvent of 1ml toluene and 1mol industrial ethanol / 1g product, obtain 136g

[0038] 4-〖trans-4′-[2″-(trans-4_-propylcyclohexyl) ethylene]cyclohexyl〗2-fluorochlorobenzene, structural formula: GC: 99.5%.

[0039] 2.2: Product 4-〖trans-4′-[2″-(trans-4_-propylcyclohexyl)ethyl]cyclohexyl〗2-fluorobenzonitrile [structural formula: ] preparation

[0040]136g (0.37mol) of 4-[trans-4'-[2"-(trans-4-propylcyclohexyl) ethylene group] cyclohexyl] 2-flu...

Embodiment 3

[0043] 3.1: According to the similar method of Example 2.1, the following compounds can be obtained

[0044] 4-〖trans-4′-[2″-(trans-4_-ethylcyclohexyl) ethylene]cyclohexyl〗2-fluorochlorobenzene, GC: 99.5%, yield: 75%, structural formula:

[0045] 4-〖trans-4′-[2″-(trans-4_-butylcyclohexyl)ethylene]cyclohexyl〗2-fluorochlorobenzene, GC: 99.5%, yield: 74%, structural formula:

[0046] 3.2: According to the similar method of Example 2.2, the following monomeric liquid crystal compounds can be obtained

[0047] 4-〖trans-4′-[2″-(trans-4_-ethylcyclohexyl)ethylene]cyclohexyl〗2-fluorobenzonitrile, mp: 70.6°C, cp: 145.6°C, [structural formula: ].

[0048] 4-〖trans-4′-[2″-(trans-4_-butylcyclohexyl)ethylene]cyclohexyl〗2-fluoro-benzonitrile, mp: 54.9°C, cp: 165.7°C, [structural formula: ].

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PUM

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Abstract

This invention relates to a preparation method for benzonitrile monomer liquid crystal, belonging to monomer liquid crystal preparation technology field. The method is characterized by the monomer liquid crystal synthesis routes, as shown in formula (I), wherein R is C1-C10 straight chain alkyl, n = 0 or 2, m = 0 or 1, A = cyclohexyl, and Y, Z = F or H, but at least one of Y and Z is H atom. The high-yield products could be obtained through using the formula (II) above as raw materials and high temperature cyanidation. The synthesis method is simple, has relatively mild reaction conditions, low cost of production, and is also environmental-friendly, therefore it is particularly suited to industrialized production of 4-(trans-4'-substituted cyclohexyl) benzonitrile monomer liquid crystal.

Description

Technical field: [0001] The invention relates to a method for preparing benzonitrile monomer liquid crystal, which belongs to the preparation method of monomer liquid crystal [0002] technology field. Background technique: [0003] 4-(trans-4'-substituted cyclohexyl) benzonitrile monomer liquid crystal has a large Δε value and good solubility, so it is widely used in TN and STN mixed liquid crystals. However, its existing synthesis process has the disadvantages of long process route, dangerous raw materials and high production cost. Merck patent DE3939116 discloses a method: use BuLi at -70 ° C to The ortho-metal ionization of fluorine, and then through a series of reactions such as carbonylation to obtain The BuLi used in this preparation process is extremely flammable and explosive, and the temperature condition of -70 ° C is difficult to achieve industrially; and the synthesis disclosed in Merck's patent DE4327749 ( ) route is: [0004] [0005] The strong bas...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C255/50C07C253/14C09K19/10
Inventor 宋有永李文斌张秀美贾公明刘鸿领相龙明
Owner VALIANT CO LTD
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