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Method for synthesizing trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethylene liquid crystal monomer

A technology of cyclohexylethylene and a synthesis method, which is applied in the synthesis field of trans-4-cyclohexylethylene liquid crystal monomer, can solve the problems of high cost, low atom utilization rate, large consumption of raw materials, etc., and achieves low cost and low avoidance. Atomic utilization, effect of avoiding environmental problems

Active Publication Date: 2018-04-27
XIAN RUILIAN NEW MATERIAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The cost of this route is high due to the high consumption of starting materials due to the low atom utilization of the reaction

Method used

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  • Method for synthesizing trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethylene liquid crystal monomer
  • Method for synthesizing trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethylene liquid crystal monomer
  • Method for synthesizing trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethylene liquid crystal monomer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] (1) Preparation of compound (A)

[0053] Under the protection of nitrogen, add 2520ml of methanol, 420.0g of trans-4-(trans-4'-n-propylcyclohexyl)cyclohexyl ethyl ketone, and 72.0g of p-toluenesulfonic acid to a dry 10L three-necked flask, and cool the system down to 20°C At ~25°C, add 357.0g of N-bromosuccinimide in batches, control the temperature at 30°C to 40°C, react for 3 hours after the addition, and stop the reaction. After concentration and recovery of methanol under reduced pressure, 2100ml of water was added, and solids were precipitated after stirring. The solids were filtered and dried to obtain 526.3g of compound A, GC>96%, and the yield was 95%.

[0054] (2) Preparation of compound (B)

[0055] Add 2770ml of methanol and 554.0g of compound A to a 10L three-necked flask successively, add 32.0g of sodium borohydride in batches, start heating to the reaction temperature of 64-97°C, reflux for 5 hours, distill out the methanol system, and pour the concentrat...

Embodiment 2

[0063] (1) Preparation of compound (A)

[0064] Under the protection of nitrogen, add 2520ml of methanol, 420.0g of trans-4-(trans-4'-n-propylcyclohexyl)cyclohexyl ethyl ketone, and 72.0g of p-toluenesulfonic acid to a dry 10L three-necked flask, and cool the system down to 20°C ~25°C, add 258.0g dibromohydantoin in batches, control the temperature at 20°C~30°C, react for 3 hours after the addition, stop the reaction, concentrate under reduced pressure to recover methanol, add 2100ml water to the concentrate and stir, and wash the precipitated solid with water until Neutral, 520.0g compound A was obtained by drying, GC>96%, yield 93.8%.

[0065] (2) Preparation of compound (B)

[0066] Add 4160ml of ethanol and 520.0g of compound (A) to a 10L three-necked flask in sequence, add 28.5g of sodium borohydride in batches, heat to a reaction temperature of 64-97°C and reflux for 4 hours, distill off the system ethanol, pour the concentrated solution into 300ml 15 % dilute hydrochl...

Embodiment 3

[0074] (1) Preparation of compound (A)

[0075] Under the protection of nitrogen, add 4000ml of methanol, 500.0g of trans-4-(trans-4'-n-propylcyclohexyl)cyclohexyl ethyl ketone, and 50.0g of p-toluenesulfonic acid to a dry 10L three-necked flask, and cool the system down to 10°C ~20°C, add 343.0g dibromohydantoin in batches, each batch interval is 10min, control temperature 10°C~20°C, react for 1h after feeding, stop reaction, concentrate under reduced pressure to recover methanol, add and stir to the concentrate, the precipitated The solid was washed with water until neutral, and dried to obtain 630.0 g of compound A, GC>96%, and the yield was 95.7%.

[0076] (2) Preparation of compound (B)

[0077] Add 3120ml of ethanol and 520.0g of compound (A) to a 10L three-necked flask in turn, add 34.2g of sodium borohydride in ten batches (10 minutes between batches) and start heating to the reaction temperature of 64-97°C, reflux for 4 hours, and distill off the system ethanol , Po...

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Abstract

The invention relates to a method for synthesizing a trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethylene liquid crystal. A desired product is prepared from trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethanone as a raw material through alpha-bromination, reduction, intramolecular etherification, ring-opening bromination and debromination alkene formation. The method has the advantages of easy availability of raw materials, high yield of various steps, easy purification of products and low cost. The entire route uses cheap toluene, ethanol and methanol as solvents, prevents the problems of lowatomic utilization and many by-products of the wittig reaction and prevents the environmental problems produced by highly concentrated tetrahydrofuran wastewater. Environmental friendliness is one ofthe highlights of the route.

Description

technical field [0001] The invention belongs to the technical field of liquid crystals, and specifically relates to a synthetic method of a class of trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethylene liquid crystal monomers. Background technique [0002] Cyclohexane-based liquid crystals are widely used in display-type mixed liquid crystals because of their high stability and wide nematic phase temperature range. Trans-4-(trans-4'-alkylcyclohexyl)cyclohexylethylene liquid crystal is widely used in It is widely used in mid-to-high-end mixed LCDs. The liquid crystal monomer has been reported as early as the 1990s. In 1996, the Japanese Takeuchi research group applied trans-4-(trans-4'-n-propylcyclohexyl)cyclohexylethylene to the liquid crystal display field for the first time, but its synthesis method was rarely reported. [0003] In 2006, Kirsch publicly reported the synthetic method of trans-4-(trans-4'-n-propylcyclohexyl)cyclohexylethylene for the first time, and its r...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C13/28C07C1/26C07C45/63C07C49/333C07C29/159C07C31/44C07D303/04C07D301/26C07C17/093C07C22/00C09K19/30
CPCC07B2200/09C07C1/26C07C17/093C07C29/159C07C45/63C07D301/26C07D303/04C09K19/3003C09K2019/3004C07C49/333C07C31/44C07C22/00C07C13/28Y02P20/52
Inventor 段迎春侯修泽巨妮娟沈宁董金盟鲍斌冯小琼高仁孝
Owner XIAN RUILIAN NEW MATERIAL CO LTD
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