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Pyran ring-containing negative liquid crystal compound and preparation method thereof

A technology for negative liquid crystals and compounds, applied in the field of negative liquid crystal compounds and their preparation, can solve the problems of poor mutual solubility, high melting point and viscosity, and lack of obvious improvement in the optical anisotropy and dielectric anisotropy of liquid crystal mixtures. , to achieve the effect of improving low temperature performance, good low temperature stability, and improving light response speed

Inactive Publication Date: 2015-07-22
SHAANXI NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the relatively high melting point and viscosity, and relatively poor miscibility with other liquid crystal chemicals, the optical anisotropy and dielectric anisotropy of the liquid crystal mixture have not been significantly improved after adding this type of liquid crystal compound (Liq .Cryst., 2012, Vol. 39, pp. 957-963)

Method used

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  • Pyran ring-containing negative liquid crystal compound and preparation method thereof
  • Pyran ring-containing negative liquid crystal compound and preparation method thereof
  • Pyran ring-containing negative liquid crystal compound and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0045] 1. Synthesis of compound b-1

[0046]Under nitrogen protection at a flow rate of 0.6mL / min, 10.00g of 4-bromo-2,3-difluorophenol (compound a-1), 6.05g of 3,4-2H-dihydropyran, 1.21g of 4- Pyridinium toluenesulfonate (PPTS, CAS number: 24057-28-1, provided by Chengdu Best Reagent Co., Ltd.) and 100 mL of anhydrous dichloromethane were added to a three-necked flask equipped with a thermometer, a magnetic stir bar, and a condenser , stirred and reacted at room temperature for 4 hours, the resulting reaction solution was diluted with saturated aqueous sodium bicarbonate solution, the organic layer was separated, the aqueous layer was extracted three times with dichloromethane, the organic phases were combined and washed with water until neutral, and dried with anhydrous magnesium sulfate Concentrate to obtain an oily liquid, and the obtained concentrated solution is subjected to column chromatography separation and purification (using silica gel as a stationary phase, and a ...

Embodiment 2

[0058] 1. Synthesis of compound b-1

[0059] The specific synthesis method is the same as Step 1 of Example 1.

[0060] 2. Synthesis of negative liquid crystal compounds containing pyran rings

[0061] In step 2 of Example 1, the 2-methyl-4-(4-trans-(4-n-propylcyclohexyl) ethylphenyl)-3-butyn-2-ol (compound c- 1) Replace with equimolar 2-methyl-4-(4-trans-(4-n-ethylcyclohexyl)ethylphenyl)-3-butyn-2-ol (compound c-2), other The steps are the same as in Example 1 to obtain white crystals—a negative liquid crystal compound containing a pyran ring, whose chemical name is 1-{4-[2-(4-n-ethylcyclohexyl)ethyl]phenyl}- 2-{4-[(2-tetrahydropyran)oxy]-2,3-difluorophenyl}acetylene, the yield is 45%, the specific reaction equation is as follows:

[0062]

[0063] The structural characterization data of the obtained negative liquid crystal compound containing pyran ring are as follows:

[0064] 13 C-NMR (CDCl 3 is the solvent, the internal standard is TMS, 75MHz, ppm): 146.0, 144.1,...

Embodiment 3

[0070] 1. Synthesis of compound b-1

[0071] The specific synthesis method is the same as Step 1 of Example 1.

[0072] 2. Synthesis of negative liquid crystal compounds containing pyran rings

[0073] In step 2 of Example 1, the 2-methyl-4-(4-trans-(4-n-propylcyclohexyl) ethylphenyl)-3-butyn-2-ol (compound c- 1) Replace with equimolar 2-methyl-4-(4-trans-(4-n-butylcyclohexyl) ethylphenyl)-3-butyn-2-alcohol (compound c-3), other steps and Same as Example 1, white crystals are obtained—a negative liquid crystal compound containing a pyran ring, and its chemical designation is 1-{4-[2-(4-n-butylcyclohexyl)ethyl]phenyl}-2-{4 -[(2-tetrahydropyran)oxy]-2,3-difluorophenyl}acetylene, the yield is 40%, and the specific reaction equation is as follows:

[0074]

[0075] The obtained negative liquid crystal compound containing a pyran ring was characterized by NMR and mass spectrometry, which indicated that it was the target product, and its optical anisotropy and dielectric aniso...

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Abstract

The invention discloses a pyran ring-containing negative liquid crystal compound. The structural formula of the compound is shown in the description, wherein R represents C2-C5 linear alkyl, values of x and y are 0 or 1, cyclohexyl is trans cyclohexyl. A preparation method for the liquid crystal compound comprises the following steps: reacting substituted phenol with 3,4-2H-dihydropyran at normal temperature to obtain pyran ring-protected halogenated hydrocarbon; performing sonogashira coupling reaction on pyran ring-protected halogenated hydrocarbon and substituted aryl alkynol to obtain the liquid crystal compound; the liquid crystal compound is simple in synthesis method, lower in cost and suitable for industrial production. The liquid crystal compound has negative dielectric anisotropy and a certain nematic liquid crystal range, has excellent low-temperature stability and appropriate optical anisotropy, has excellent solubility with other liquid crystal compounds, and can be applied to an IPS display mode, a VA-TFT display mode and a dual-frequency liquid crystal display mode.

Description

technical field [0001] The invention belongs to the technical field of liquid crystal compounds, and in particular relates to a negative liquid crystal compound containing a pyran ring and a preparation method thereof. Background technique [0002] Since the application of liquid crystal materials in optoelectronic displays in the 1970s, liquid crystals have achieved remarkable achievements as display materials. However, so far a single liquid crystal material still cannot meet many requirements of display materials, such as low viscosity, low threshold (large dielectric anisotropy), large birefringence, wide nematic phase interval, high-definition bright spots, etc., so it is necessary to develop performance Different new liquid crystal monomers, and then mix a variety of liquid crystal compounds in an appropriate proportion in order to obtain the best match of various special parameters to meet various display requirements. [0003] In the liquid crystal display element, ...

Claims

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Application Information

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IPC IPC(8): C09K19/34C07D309/12
Inventor 安忠维陈然陈新兵陈沛
Owner SHAANXI NORMAL UNIV
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