2,3,2,'3' tetrafluoro diphenyl acetylene derivative, its composition, preparation method and use

A technology of tetrafluorotoluene and its derivatives, which is applied in 2 fields and can solve problems such as insufficient effectiveness

Inactive Publication Date: 2007-02-14
SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, these liquid crystal compounds Δn, Δε are still limited and insufficiently effective
[0024] So far, no single liquid cr...

Method used

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  • 2,3,2,'3' tetrafluoro diphenyl acetylene derivative, its composition, preparation method and use
  • 2,3,2,'3' tetrafluoro diphenyl acetylene derivative, its composition, preparation method and use
  • 2,3,2,'3' tetrafluoro diphenyl acetylene derivative, its composition, preparation method and use

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0094] Preparation of 4-propyl-4`-ethoxy-2,3,2`,3`-tetrafluorobenzil.

[0095]

[0096] Step 1-1: Synthesis of 4-ethoxy-2,3-difluoroiodobenzene: Add 52g (0.37mol) 2,3-difluorophenetole, 250ml dry tetrafluorofuran into a three-necked flask, and lower the temperature under nitrogen protection At -70°C, start to add 0.45mol of n-butyllithium dropwise for about half an hour. After the addition is complete, keep it at -70°C for 1.5 hours. Add dropwise for 1 hour, after dropping, keep for 1 hour; slowly add 10% NaHSO 3 Solution until discolored, separated, the organic layer was washed twice with water, anhydrous MgSO 4 Dry, filter off the desiccant, evaporate to dryness to obtain 88g, gas chromatography purity: 95%, yield: 81%.

[0097]Step 2-1: Synthesis of 4-propyl-2,3-difluoroiodobenzene: Add 117g (0.75mol) propyldifluorobenzene and 600ml dry THF into a three-necked flask, and cool down to -70°C under nitrogen protection Start to add 0.9 mol of n-butyllithium dropwise, cont...

Embodiment 2

[0105] Preparation of trans-4-propylcyclohexyl-4`-ethoxy-2,3,2`,3`-tetrafluorobenzil.

[0106]

[0107] Step 1-1: Synthesis of propylcyclohexene-2,3-difluorobenzene: Add 114g (1mol) of o-difluorobenzene and 300ml of dry THF into a three-necked flask, install and stir, cool down to -70°C under nitrogen protection, and start Add 1.1mol of n-butyllithium dropwise, control the temperature at -70°C, add dropwise for about 1 hour, after dropping, keep for 1 hour, then add 126g (0.9mol) of acetone dropwise at -70°C Add dropwise for about 1 hour, and keep for 4-5 hours after the drop is completed. Pour into about 1.5L of water for hydrolysis, extract with 500ml×3 toluene, combine organic phases, wash with water until neutral, divide into clean water, add another three-neck flask, add 5g of p-toluenesulfonic acid, heat up while stirring, and distill THF , when the internal temperature reaches 108°C, stop the distillation, change to a reflux condenser, and reflux for 5-6 hours. Aft...

Embodiment 3

[0120] Preparation of trans 4-pentylcyclohexyl-4`-ethoxy-2,3,2`,3`-tetrafluorobenzil

[0121]

[0122] With reference to the synthetic method in Example 2, the difference is that the acetone in step 1-1 is replaced with pentanecyclone, reacted with 2,3-difluorophenyllithium reagent, and undergoes dehydration, hydrogenation, transposition, Iodination gives 4-pentylcyclohexyl-2,3-difluoroiodobenzene, which is then coupled with 4-ethoxy-2,3-difluorophenylacetylene, and its total yield is 38%. The experimental results are as follows:

[0123] (1) Assay by gas chromatography: >99.7%.

[0124] (2) Compound phase structure: C: 84.5°C N: 208.7°C I. I

[0125] molecular formula

Characteristic ions (M / Z + ) and abundance (%)

C 27 h 30 f 4 o

446(M+，100)，390(14.80)，305(5.78)，292(42.71)，279(20.15)，266(9.78)，

[0126] Elemental analysis:

[0127] Theoretical calculated values: C: 72.63%, H: 6.77%.

[0128] Experimental values: C: 72.61%, H: ...

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Abstract

The present invention relates to one kind of 2, 3, 2', 3'-tetrafluoro acetylene derivative and its composition, preparation process and use. The compound has the general expression as shown, relatively great optical anisotropy, relatively great negative dielectric anisotropy, relatively high light and heat stability and relatively low viscosity. The compound may constitute well behaved nematic phase liquid crystal composition with low threshold voltage, low viscosity, high response speed, improved response characteristic and contrast, and the nematic phase liquid crystal composition may be used in liquid crystal display of TN mode, STN mode, TFT mode, PDLC mode, etc. In addition, the compound has facile material and simple synthesis path, and the process is suitable for industrial production.

Description

technical field [0001] The present invention relates to a kind of 2,3,2',3'-tetrafluorotoluene derivatives, the composition containing 2,3,2',3'-tetrafluorotoluene derivatives and its preparation method and its The use as a liquid crystal material for display belongs to the field of compounds. Background technique [0002] Liquid crystal materials are developing rapidly along with the development of liquid crystal displays. Among them, nematic liquid crystal materials for display are the fastest growing and the largest type of liquid crystal materials in the market. Nematic liquid crystal displays have TN (twisted nematic phase) Mode, STN (Super Twisted Nematic) mode, TFT (Thin Film Transistor) mode, PDLC (Polymer Dispersed Liquid Crystal) mode, GH (Guest Host) mode, ECB (Electrically Controlled Birefringence) mode and other liquid crystal displays, especially in recent years People's demand for large size, wide viewing angle, and fast response has further promoted the mass...

Claims

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Application Information

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IPC IPC(8): C07C43/247C07C41/01C07C25/24C07C17/26C09K19/30C09K19/18
Inventor 刘鑫勤韩耀华吕文海邵哲田会强
Owner SHIJIAZHUANG CHENGZHI YONGHUA DISPLAY MATERIALS CO LTD
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