Preparation method of 1,3-propanediol derivatives and intermediates

A technology of propylene glycol and derivatives, which is applied in the field of preparation of 1,3-propanediol derivatives and intermediates, and can solve problems such as high cost, complicated process, and environmental protection

Active Publication Date: 2014-01-22
LIANHE CHEM TECH +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The technical problem solved by the present invention is to overcome the defects of the existing 2-(4-n-propylcyclohexyl)-1,3-propanediol preparation method with complex proc

Method used

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  • Preparation method of 1,3-propanediol derivatives and intermediates
  • Preparation method of 1,3-propanediol derivatives and intermediates
  • Preparation method of 1,3-propanediol derivatives and intermediates

Examples

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Embodiment 1

[0079] Preparation of dimethyl 2-(4-n-propylcyclohexylene)-1,3-malonate

[0080] Under the protection of nitrogen, add 284g (1.5mol) titanium tetrachloride and 1425g dichloromethane to the 2L reaction flask, cool down, add dropwise 84g (0.6mol) propyl cyclohexanone and A mixed solution of 95g (0.72mol) dimethyl malonate and 285g THF, after dropping, keep warm for 1h, add 220g (3mol) diethylamine dropwise at -5°C ~ 0°C, after dropwise, keep warm for 2h, then Raise the temperature to 5°C, keep the heat for another 4 hours, and control the reaction until GC (propyl cyclohexanone) < 0.5%. After passing the test, transfer the reaction solution to a 5L beaker, add 500g of water to wash, let stand to separate the liquid, and use 50g of di Chloromethane stripped the water layer again, combined the organic layers, evaporated about 1442g of solvent under reduced pressure, cooled the system to 25°C, added 300g of petroleum ether for extraction, washed twice with 250g of 5% NaCl solution,...

Embodiment 2

[0082] Preparation of dimethyl 2-(4-n-propylcyclohexylene)-1,3-malonate

[0083] Under the protection of nitrogen, add 284g (1.5mol) titanium tetrachloride and 1425g dichloromethane to the 2L reaction flask, cool down, add dropwise 84g (0.6mol) propyl cyclohexanone and A mixed solution of 95g (0.72mol) dimethyl malonate and 285g THF, after dropping, keep warm for 1h, add 93.3g (3mol) methylamine dropwise at -5°C ~ 0°C, after dropwise, keep warm for 2h, then Raise the temperature to 5°C, keep the heat for another 4 hours, and control the reaction until GC (propyl cyclohexanone) < 0.5%. After passing the test, transfer the reaction solution to a 5L beaker, add 500g of water to wash, let stand to separate the liquid, and use 50g of di Chloromethane stripped the water layer again, combined the organic layers, evaporated about 1442g of solvent under reduced pressure, cooled the system to 25°C, added 300g of petroleum ether for extraction, washed twice with 250g of 5% NaCl solution,...

Embodiment 3

[0085] Preparation of dimethyl 2-(4-n-propylcyclohexylene)-1,3-malonate

[0086]Under the protection of nitrogen, add 284g (1.5mol) titanium tetrachloride and 1425g dichloromethane to the 2L reaction flask, cool down, add dropwise 84g (0.6mol) propyl cyclohexanone and A mixed solution of 95g (0.72mol) dimethyl malonate and 285g THF, after dropping, keep warm for 1h, add 135.2g (3mol) dimethylamine dropwise at -5℃~0℃, after dropping, keep warm for 2h, Then raise the temperature to 5°C, keep the temperature for another 4 hours, and control the reaction until GC (propyl cyclohexanone) <0.5%. After passing the test, transfer the reaction solution to a 5L beaker, add 500g of water to wash, let stand to separate the liquid, and use 50g The dichloromethane back-extracted the water layer once more, combined the organic layers, evaporated about 1442g of solvent under reduced pressure, cooled the system to 25°C, added 300g of petroleum ether for extraction, washed twice with 250g of 5% ...

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Abstract

The invention discloses a preparation method of 1,3-propanediol derivatives and intermediates. The preparation method of trans-2-(4-n-propylcyclohexyl)-1,3-propanediol comprises the following steps: (1) carrying out coupling reaction on propyl cyclohexanone and dimethyl malonate in a solvent under the action of organic alkali and titanium tetrachloride in an inert gas protective atmosphere; (2) reacting the product of the step (1) with hydrogen in an organic solvent under the catalytic action of palladium-carbon; and (3) carrying out reduction reaction on the product of the step (2) with sodium borohydride and lithium chloride in an ethanol-water mixed solution. The preparation method avoids using pyridine, THF (tetrahydrofuran) and other expensive raw materials, reduces the cost, lowers the requirements for wastewater treatment equipment, has the advantages of high safety, high efficiency and environmental protection, and can easily implement industrial production.

Description

technical field [0001] The invention relates to a preparation method of 1,3-propanediol derivatives and intermediates. Background technique [0002] The 1,3-propanediol liquid crystal intermediate is mainly used to synthesize dioxane liquid crystal monomers, which can be used to prepare liquid crystal compositions with high resistivity, low power consumption, low driving threshold voltage, and low viscosity. Among them, trans 2-(4-n-propylcyclohexyl)-1,3-propanediol is a widely used liquid crystal intermediate. [0003] In the method for synthesizing 2-(4-n-propylcyclohexyl)-1,3-propanediol, the most commonly used is to adopt following two kinds: [0004] Method 1, using propyl cyclohexanone as a raw material, undergoing hydrogenation reduction with hydrogen, esterification of methylsulfonyl chloride, coupling with dimethyl malonate, reduction and other reactions to obtain the product. (See references Organic Process Research & Development2004,8,389-395 for details) The sy...

Claims

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Application Information

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IPC IPC(8): C07C31/27C07C29/149C07C69/34C07C69/608C07C67/303C07C67/343
CPCC07C29/147C07C67/303C07C67/343C07C2601/14C07C31/276C07C69/608
Inventor 郭章红江朋陈庆忠李强沈启富
Owner LIANHE CHEM TECH
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