Process for synthesizing liquid crystal compounds containing 1,3-dioxane

A technology for dioxane and liquid crystal compounds, which is applied in the field of compound synthesis, can solve the problems of high operation risk, high price, fire, etc., and achieves the effects of safe operation, easy storage and simple feeding method.

Inactive Publication Date: 2009-04-15
BEIJING BAYI SPACE LCD MATERIALS TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0029] The above three reducing agents are all expensive, ignite in contact with water and air, and are highly dangerous to operate.

Method used

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  • Process for synthesizing liquid crystal compounds containing 1,3-dioxane
  • Process for synthesizing liquid crystal compounds containing 1,3-dioxane
  • Process for synthesizing liquid crystal compounds containing 1,3-dioxane

Examples

Experimental program
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Effect test

Embodiment 1

[0037] In this example, the compound of formula (I) is butyl malonate diethyl ester, and butyl propanediol is prepared by hydrogenation reduction reaction to illustrate the hydrogenation reduction reaction of alkyl succinate ethyl ester.

[0038]

[0039] 216g of potassium borohydride, 170g of anhydrous lithium chloride and 1500ml of tetrahydrofuran were mixed, cooled externally with ice water, and a mixed solution of 216g of butyl malonate and 200ml of tetrahydrofuran was added dropwise. After complete addition, the reaction mixture was heated to reflux and reacted for 8-20 hours, monitoring the complete reaction of raw materials. Slowly pour 2kg of crushed ice and 1L of deionized water into the reaction solution, then add 500ml of petroleum ether and stir for 10 minutes, separate the organic phase and extract the water phase with petroleum ether twice, combine the organic phases, wash with deionized water until neutral, and dry , and the solvent was removed under reduced ...

Embodiment 2

[0046] The obtained alkyl propylene glycol is reacted with the compound of formula (III) to obtain a liquid crystal compound containing 1,3-dioxane.

[0047]

[0048] The 117g butylpropanediol that embodiment 1 obtains, 6g p-toluenesulfonic acid, 115g p-cyanobenzaldehyde and 800ml toluene are mixed. Stir and heat to reflux at 110°C to separate water for 4 hours until no water drops are formed. Cool down to 50°C, wash with water until neutral, dry over anhydrous sodium sulfate, remove the solvent under reduced pressure, and recrystallize twice with 400ml of absolute ethanol to obtain white crystals of 4-(5-butyl-1,3-dioxane Alk-2-)benzonitrile (1).

[0049] Yield: 162 g (75% of theory), GC: 99.60%, melting point: 44.4°C, clearing point: 34.8°C.

[0050] According to the above-mentioned similar method, the following monomeric liquid crystals can be obtained:

[0051] 4-(5-Ethyl-1,3-dioxane-2-)benzonitrile;

[0052] 4-(5-Propyl-1,3-dioxane-2-)benzonitrile;

[0053] 4-(5-p...

Embodiment 3

[0072] This example prepares butyl propanediol by hydrogenation reduction of the compound of formula (b), in order to illustrate the hydrogenation reduction reaction of ethyl cyclohexyl succinate.

[0073]

[0074] 216g of potassium borohydride, 170g of anhydrous lithium chloride and 1500ml of tetrahydrofuran were mixed, cooled externally with ice water, and a mixed solution of 284g of the compound of formula (2) and 200ml of tetrahydrofuran was added dropwise. After complete addition, the reaction mixture was heated to reflux and reacted for 8-20 hours, monitoring the complete reaction of raw materials. Slowly pour 2kg of crushed ice and 1L of deionized water into the reaction solution, then add 500ml of petroleum ether and stir for 10 minutes, separate the organic phase and extract the water phase with petroleum ether twice, combine the organic phases, wash with deionized water until neutral, and dry , and the solvent was removed under reduced pressure to obtain light yel...

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Abstract

The invention provides a method for synthesizing a liquid crystal compound containing 1, 3-dioxahexane, which comprises procedures of hydrogenating and reducing alkyl or alkyl cyclohexyl diethyl malonate into alkyl or alkyl cyclohexyl propanediol by a reducing agent. With the method for synthesizing the liquid crystal compound containing 1, 3-dioxahexane, a compound composed by potassium borohydride and anhydrous lithium chloride is adopted as the reducing agent which is easy to be preserved; the batch charging method is simple; and the yield coefficient of the reaction is relatively ideal, with low cost and safe operation.

Description

technical field [0001] The invention relates to a synthesis method of compounds, in particular to a synthesis method of a class of liquid crystal compounds containing 1,3-dioxane. The compound is a liquid crystal material and is mainly used for liquid crystal displays. Background technique [0002] Since the 1970s, with the development of liquid crystal optics, liquid crystal chemistry, and large-scale integrated circuits and liquid crystal materials, the application of liquid crystals in display has achieved rapid development, and has successively experienced TN-LCD, STN-LCD , TFT-LCD three stages. Its typical applications include watches, calculators, instruments and meters, and later MP3 and MP4, which are now widely used in LCD TVs. Liquid crystal display has the advantages of flat plate, light weight, low energy consumption, low radiation, etc., and the processing technology is continuously improved, the cost is continuously reduced, and its popularity rate is rapidly ...

Claims

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Application Information

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IPC IPC(8): C07C31/20C07C29/147C07D319/06C09K19/06
Inventor 姜天孟杭德余田会强黄宇鹏储士红王名贤
Owner BEIJING BAYI SPACE LCD MATERIALS TECH
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