Method for converting cis-substituted cyclohexyl in organic molecules into trans-substituted cyclohexyl

A cis, organic technology, applied in organic chemistry, organic isomerization, chemical instruments and methods, etc., can solve the problems of limited selection of passivation catalysts, large amount of transposition catalysts, low temperature tolerance, etc., to achieve inhibition The effect is good, the transposition method is simple and easy, and the effect of long reaction time range

Active Publication Date: 2013-12-25
江苏广域化学有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But there is following deficiency in this method: 1. this method is only applicable to the conversion method of the cis and trans isomers of alkylcyclohexylbenzene derivatives
2. In this method, the consumption of transposition catalyst is too large, which increases the production cost. 3. The catalyst of passivation in this method is only the complex compound of aluminum trichloride and ethers. For different substituted cyclohexyl derivatives, Limited choice of passivation catalysts
4. The temperature of the transposition reaction is -15°C to 5°C, and the reaction is not very tolerant to temperature

Method used

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  • Method for converting cis-substituted cyclohexyl in organic molecules into trans-substituted cyclohexyl
  • Method for converting cis-substituted cyclohexyl in organic molecules into trans-substituted cyclohexyl
  • Method for converting cis-substituted cyclohexyl in organic molecules into trans-substituted cyclohexyl

Examples

Experimental program
Comparison scheme
Effect test

Synthetic example 1

[0058] Synthetic Example 1: Transposition of 4-(4'-propylcyclohexyl)cyclohexylbenzene (cis: trans = 70:30 in raw materials).

[0059]

Embodiment 1

[0061] The synthetic route of synthetic example 1 is adopted. Anhydrous aluminum trichloride-triethylamine hydrochloride mixture is used as a catalyst; the solvent is petroleum ether, and the temperature is 5-10°C.

[0062] Experimental operation:

[0063] In a 100ml three-necked flask, first add 0.1mol of triethylamine and 60ml of petroleum ether (90-120°C). Then accurately add 0.105 mol of hydrochloric acid aqueous solution dropwise under stirring. Stir at room temperature for 30 minutes after dropping. Heat under stirring until the petroleum ether refluxes, and use a water separator to clean the water brought out by the reflux. After no water comes out, cool down to room temperature, and add 0.105 mol of anhydrous aluminum trichloride while stirring. Stirring was continued at room temperature for 1 hour after the addition was complete. Stirring was stopped, and it was found that all the solids were dissolved, and the reaction solution was divided into two layers: the u...

Embodiment 2

[0071] The synthetic route of synthetic example 1 is adopted. Anhydrous aluminum trichloride-nitrobenzene mixture is used as a catalyst; the solvent is dichloromethane, and the temperature is 10-15°C.

[0072] Experimental operation:

[0073] The cis: trans = 70:30 raw material samples were dried, and the water and polar solvents were completely removed for later use.

[0074] Into a 100ml three-necked flask, add 60ml of dichloromethane and 0.50g of nitrobenzene. Add 0.5 g of anhydrous aluminum trichloride quickly at room temperature. After the addition, maintain room temperature and argon protection, and stir for more than 1 hour. Stir and cool down to the temperature of the reaction solution at 10-15° C., and quickly add 30 g of the above-mentioned spare raw material samples under the protection of argon. Maintain stirring and liquid temperature at 10-15°C. About 5ml of the reaction solution was taken out at regular intervals, washed with 20ml of 5% hydrochloric acid, a...

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Abstract

The invention relates to a method for converting cis-substituted cyclohexyl into trans-substituted cyclohexyl. The cis-substituted cyclohexyl has a structural formula shown in the specifications, wherein R and R' are the same or different and are an H atom, fatty hydrocarbyl with 1 to 10 carbon atoms, or aromatic hydrocarbyl with 1 to 10 carbon atoms; X and X' are the same or different and are an H element, 1 to 3 halogens, cyan, alkyl, alkoxy, trifluoromethyl or trifluoromethoxy; a catalyst converted from an isomer is weakened aluminum trichloride of which the activity is weakened by a weakening additive, or tetrachloroaluminate; and the reaction temperature is between -20 and +50 DEG C. The conversion method is simple and practicable, other isomerization side reactions in the cyclohexyl conversion process can be effectively inhibited when cyclohexyl conversion reaction is performed, a few isomerization byproducts are generated, yield is high, and a wide application prospect is achieved.

Description

technical field [0001] The invention relates to a method for transposition of organic compound cis-trans isomers, in particular to a method for converting cis-substituted cyclohexyl into trans-substituted cyclohexyl. Background technique [0002] Organic substances containing one or more substituted cyclohexyl groups are a very useful class of substances. More than 70% of the molecules of liquid crystal monomers used in current liquid crystal materials contain one or more substituted cyclohexyl groups. In the preparation process of such molecules, cis-trans isomers are often generated simultaneously, of which the trans-form product can be used in liquid crystals, and the cis-form product is a by-product, generally accounting for 30%-60% of the total yield , need to be removed. In the process of removing the cis-form product, more trans-form products will be lost at the same time, resulting in a significant increase in the production cost of such liquid crystal monomers. ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07B37/08C07C13/28C07C5/22C07C25/18C07C17/358B01J31/26B01J27/125
Inventor 宋斌李卫红余俊安李宇
Owner 江苏广域化学有限公司
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