Method for in situ preparing o-vanillin by taking pyrocatechol as raw material

A technology of ortho-vanillin and catechol, which is applied in the field of preparation of pharmaceutical raw materials, can solve the problems of restricting the large-scale production of berberine drugs, the difficulty of separating isomer mixtures, and the lack of product quality assurance, and achieve economic benefits and Significant social benefits, overcoming production constraints, and cheap prices

Inactive Publication Date: 2019-04-23
SHENYANG INSTITUTE OF CHEMICAL TECHNOLOGY
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  • Summary
  • Abstract
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Problems solved by technology

[0003] At present, there is no report on the industrial production of ortho-vanillin. It is only obtained as a by-product of vanillin production after purification and separation. The annual output of vanillin in my country is about 10,000 tons, distributed in 14 enterprises, with a kiloton level There are only two companies, and there are two companies with hundreds of tons of ortho vanillin, and the product quality is not guaranteed, there are many impurities, and subject to the difficulty of separating isomer mixtures, the so-called analytically pure ortho vanillin in the market Berberine also contains isomer impurities, which seriously restricts the large-scale production of berberine drugs in both yield and quality, which is a strategic issue
[0004] Taking guaiacol as raw material through formylation reaction, due to the low selectivity, only the mixture of vanillin and ortho-vanillin can be obtained; Removal of sulfonic acid, continue electrolytic oxidation, deshrinkage and extraction to prepare ortho-vanillin, which has not been industrialized due to the limitation of electrolytic oxidation process; from 5-formyl vanillin, dealdehyde group under catalytic conditions, combined with The preparation of ortho-vanillin by falling film distillation is also limited to experimental research

Method used

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  • Method for in situ preparing o-vanillin by taking pyrocatechol as raw material

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Embodiment approach

[0026] (1) According to the mass ratio of 1:4, weigh catechol and sodium hydroxide, put them into a 500ml three-necked flask, add catalysts (alcohols), use methanol as a solvent, heat up and stir until the solid dissolves, and at 65°C, Add 2-chloromethane dropwise, keep warm for 3 hours, filter, concentrate under reduced pressure to recover the solvent, extract with cyclohexane, and distill off methanol to obtain the product o-methoxyphenol.

[0027] (2) Using acetonitrile as solvent, weigh 18g o-methoxyphenol, pour it into a 500ml three-neck flask, add catalyst (Lewis acid), heat up and stir to 65°C, add triethylamine dropwise, add paraformaldehyde, slowly Raise the temperature to reflux, react for 1 h, drop to room temperature and add hydrochloric acid to adjust the pH value to obtain the ortho-vanillin reaction solution.

[0028] (3) Sodium chloride was added to the reaction solution, the solution was layered, and chromatographically separated to obtain a mixture of acetoni...

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Abstract

A method for in situ preparing o-vanillin by taking pyrocatechol as the raw material and relates to production methods of drug materials. The method comprises, firstly, taking the pyrocatechol with apurity degree of 99 w% as the raw material; secondly, taking absolute ethyl alcohol as solvent and polyethylene glycol and sodium hydroxide as catalysts; thirdly, taking acetonitrile as solvent, triethylamine as acid-binding agent and magnesium chloride as catalysts; fourthly, adding sodium chloride into reaction liquid, performing chromatographic layering, and removing a water layer; fifthly, cooling raffinate down to -10 DEG C for freezing concentration, and performing rotary evaporation and separation to obtain oily 2-hydroxy-3-methoxybenaldehyde. The raw material applied is a bulk organicraw material of the pyrocatechol, which is easy to acquire and low in price; by means of the technical processes of methylation and then formylation, the method for in situ preparing the o-vanillin bytaking the pyrocatechol as the raw material can shorten the technical process and reduce the cost, thereby being applicable to industrial production of the o-vanillin, overcoming the limitation of yield of the o-vanillin and achieving significant economic and social benefits.

Description

technical field [0001] The invention relates to a preparation method of a drug raw material, in particular to a method for preparing o-vanillin by using catechol as a raw material. Background technique [0002] Ortho-vanillin is an important intermediate in medicine and organic synthesis. 2,3-dimethoxytoluene, 1,2,3-trimethoxybenzene, brominated ortho piperonal, novolac epoxy resin and 2,3-dimethoxy O-vanillin is an important raw material for the production of berberine. [0003] At present, there is no report on the industrial production of ortho-vanillin. It is only obtained as a by-product of vanillin production after purification and separation. The annual output of vanillin in my country is about 10,000 tons, distributed in 14 enterprises, with a kiloton level There are only two companies, and there are two companies with hundreds of tons of ortho vanillin, and the product quality is not guaranteed, there are many impurities, and subject to the difficulty of separating...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C41/16C07C43/23C07C45/49C07C47/575
CPCC07C41/16C07C45/49C07C43/23C07C47/575
Inventor 王国胜奚洋齐飞韩思宇谢英鹏聂鑫孟召宾
Owner SHENYANG INSTITUTE OF CHEMICAL TECHNOLOGY
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