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Preparation method of 1,3-cyclohexanedione

A technology of cyclohexanedione and acetone dicarboxylate, which is applied in the field of preparation of 1,3-cyclohexanedione, can solve problems such as low reaction conversion rate and yield, increased risk, and high environmental pressure, and achieves High production efficiency, low pollution, and high-efficiency synthesis

Active Publication Date: 2020-05-22
山东亘元新材料股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, most of the resorcinol reduction methods use noble metal catalysts, and the reaction conversion rate and yield are low. If ordinary metal catalysts are used, the dosage is large, the environmental pressure is relatively large, and the cost is high.
For example: Japanese patent JP04013644A uses resorcinol as a raw material, and after amine neutralization, 5% Pd / C catalytic hydrogenation is used to prepare 1,3-cyclohexanedione, and the conversion rate of resorcinol is greater than 99%, but 1, The selectivity of 3-cyclohexanedione is only 79.6%
Another example: Japanese patent JP 2001342163 uses resorcinol as a raw material, and after amine neutralization, catalyzes hydrogenation with Raney nickel to prepare 1,3-cyclohexanedione. The conversion rate of resorcinol is 90.2%, and 1,3- The selectivity of cyclohexanedione is 91.0%, and the dosage of Raney nickel is 18% by weight of resorcinol. Raney nickel is a highly flammable catalyst, which increases the danger in the production process

Method used

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  • Preparation method of 1,3-cyclohexanedione
  • Preparation method of 1,3-cyclohexanedione

Examples

Experimental program
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Effect test

Embodiment 1

[0027] A preparation method for 1,3-cyclohexanedione, comprising the steps of:

[0028] (1) Under the protection of nitrogen, add 250ml of anhydrous methanol to a 500ml three-necked flask equipped with a thermometer, reflux condenser and mechanical stirring, add 0.2mol of sodium methylate, stir to dissolve, and then add 1mol of 1,3-acetonedicarboxylic acid dimethyl ester, slowly add 1mol methyl acrylate dropwise, control the internal temperature at 25-30°C, stir at this temperature for 1h, then heat the reaction solution to 60°C, add 1.8mol sodium methoxide, stir for 4h, after the reaction is completed, concentrate and remove Anhydrous methanol, the residue is the intermediate;

[0029] (2) in the 1000ml there-necked flask that thermometer, reflux condenser and mechanical stirring are housed, add the sodium hydroxide aqueous solution of 400g mass concentration 20%, then add the intermediate that step (1) makes, be heated to 70-80 ℃, After 2 hours, add concentrated hydrochlori...

Embodiment 2

[0032] A preparation method for 1,3-cyclohexanedione, comprising the steps of:

[0033] (1) Under nitrogen protection, add 250ml of absolute ethanol to a 500ml three-necked flask equipped with a thermometer, reflux condenser and mechanical stirring, add 0.2mol of sodium ethylate, stir to dissolve, then add 1mol of 1,3-acetonedicarboxylic acid diethyl ester, slowly add 1mol ethyl acrylate dropwise, control the internal temperature at 25-30°C, stir at this temperature for 1h, then heat the reaction solution to 80°C, add 1.8mol sodium ethylate, stir for 4h, after the reaction is completed, concentrate and remove Absolute ethanol, the residue is the intermediate;

[0034] (2) in the 1000ml there-necked flask that thermometer, reflux condenser and mechanical stirring are housed, add the sodium hydroxide aqueous solution of 400g mass concentration 20%, then add the intermediate that step (1) makes, be heated to 70-80 ℃, After 2 hours, add concentrated hydrochloric acid dropwise to ...

Embodiment 3

[0037] A preparation method for 1,3-cyclohexanedione, comprising the steps of:

[0038] (1) Under nitrogen protection, add 250ml of anhydrous methanol to a 500ml three-necked flask equipped with a thermometer, reflux condenser and mechanical stirring, add 0.3mol of potassium carbonate, stir to dissolve, add 1mol of 1,3-acetone dicarboxylic acid dimethyl ester, slowly add 1mol methyl acrylate dropwise, control the internal temperature at 25-30°C, stir at this temperature for 1.5h, then heat the reaction solution to 70°C, add 2.7mol potassium carbonate, stir for 5h, after the reaction is complete, concentrate Remove anhydrous methanol, the residue is the intermediate;

[0039] (2) in the 1000ml there-necked flask that thermometer, reflux condenser and mechanical stirring are housed, add the sodium hydroxide aqueous solution of 400g mass concentration 10%, then add the intermediate that step (1) makes, be heated to 80-90 ℃, After 2 hours, add acetic acid dropwise to adjust the p...

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Abstract

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 1,3-cyclohexanedione. The preparation method of the 1,3-cyclohexanedione comprises the following steps: with 1,3-acetonedicarboxylic ester and acrylate as raw materials, carrying out condensation and cyclization under the action of a base catalyst to prepare an intermediate; carrying out hydrolysis decarboxylation on the intermediate to obtain a crude product; and recrystallizing the crude product to obtain the 1,3-cyclohexanedione. The preparation method of the 1,3-cyclohexanedione hasthe advantages that process conditions are convenient to realize, post-treatment operation process is simple, yield is as high as 90.9%, reaction selectivity is high, production efficiency is high, operation safety is high, pollution is small, and the preparation method is suitable for industrial scale production.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 1,3-cyclohexanedione. Background technique [0002] 1,3-Cyclohexanedione is an essential intermediate for the synthesis of herbicides sulcotrione and mesotrione, as well as the synthesis of carvedilol, a special drug that protects the cardiovascular system and treats high blood pressure, and anthrandansetone, an antiemetic drug. important intermediates. [0003] There are mainly two kinds of existing synthetic methods: condensation method and resorcinol reduction method. Among them, the condensation method uses resorcinol as the raw material, and synthesizes 1,3-cyclohexanedione through neutralization, hydrogenation reduction or hydrogen transfer reduction, acidification and rearrangement; the resorcinol reduction method uses sodium alkoxide As a condensation agent, acrylonitrile and acetone carry out Michael addition reaction, and the additio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C49/403C07C45/65C07C45/81
CPCC07C45/65C07C45/81C07C67/347C07C2601/14C07C49/403C07C69/757
Inventor 李维平孙朋波张志德
Owner 山东亘元新材料股份有限公司
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