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Method for preparing protocatechuic aldehyde from vanillin

A technology of protocatechuic aldehyde and vanillin, which is applied in the field of preparing protocatechuic aldehyde, can solve the problems of high energy consumption and long reaction time, and achieve the effects of increasing reaction temperature, good solubility, and reducing post-processing difficulty

Inactive Publication Date: 2011-11-16
HEBEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method overcomes the serious pollution caused by the use of halogenated alkanes as the reaction solvent in the current process of preparing protocatechualdehyde from vanillin, as well as the shortcomings of long reaction time and high energy consumption.

Method used

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  • Method for preparing protocatechuic aldehyde from vanillin
  • Method for preparing protocatechuic aldehyde from vanillin
  • Method for preparing protocatechuic aldehyde from vanillin

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) add 7.8g (51mmol) vanillin (technical grade, China Chemical Industry Group Co., Ltd.) and 30ml dimethyl carbonate in the there-necked flask equipped with stirring and condensation reflux device, after fully stirring, add 9.4g (70mmol) ) anhydrous AlCl 3 ;

[0027] (2) After the solid is dissolved, place the three-necked flask in an ice-water bath, and keep its temperature at 0 to 5°C; add 13.5 ml of pyridine under stirring;

[0028] (3) the reaction system was warmed up to 80 ° C, and reacted for 4 hours;

[0029] (4) after the temperature of the reaction system is lowered to room temperature, add 70 ml of dilute hydrochloric acid with a mass fraction of 12% to pH 2 under stirring conditions, and continue to stir to stop the reaction after 1.0 hours;

[0030] (5) Pour the reaction solution into a separatory funnel, leave it to stand, extract unreacted vanillin in the water phase three times with dichloromethane (20ml×3), then dichloromethane is removed by distilla...

Embodiment 2～7

[0037] The chemical reagent consumption and the reaction steps are the same as in Example 1, but the reaction time in the step (3) is changed, and the reaction results are shown in Table 1.

[0038] Table 1 Influence of reaction time on the preparation of protocatechuic aldehyde from vanillin

[0039]

Embodiment 8～11

[0041] The chemical reagent consumption and the reaction steps are the same as in Example 1, but the reaction temperature in the step (3) is changed, and the reaction results are shown in Table 2.

[0042] Table 2 Influence of reaction temperature on the preparation of protocatechualdehyde from vanillin

[0043]

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Abstract

The invention relates to a method for preparing protocatechuic aldehyde from vanillin. The method comprises the following steps: (1) adding vanillin and a solvent into a reactor, wherein the use amount of the solvent is 1-10 ml / g vanillin; fully stirring, and adding a demethylation reagent, wherein the molar ratio of the vanillin to the demethylation reagent is 1:(0.6-1.6); (2) maintaining the reactor temperature at 0-10 DEG C, and adding pyridine, wherein the use amount of the pyridine is 0.5-2.6 ml / g vanillin; (3) raising the reaction system temperature to 30-90 DEG C, and reacting for 2-16 hours; (4) adding 12wt% diluted hydrochloric acid under stirring condition for acidifying to pH 2-4, continuously stirring for 0.5-1.0 hour, and stopping reaction; (5) extracting the reaction liquid with dichloromethane; and (6) then extracting the raffinate phase with ethyl acetate, drying, distilling and purifying to obtain protocatechuic aldehyde. In the method provided by the invention, an environmentally-friendly carbonate solvent is used to substitute for the dichloromethane solvent, the reaction temperature is increased and the reaction time is greatly shortened; and when ZnCl2 is used as the demethylation reagent, the equipment corrosion problem caused by the use of AlCl3 can be reduced.

Description

technical field [0001] The invention relates to a method for preparing protocatechualdehyde, in particular to a method for preparing protocatechualdehyde using vanillin as a raw material in an environment-friendly solvent. It is environmentally friendly and provides an efficient and safe production method and operating conditions for preparing high-yield and high-purity protocatechualdehyde in industrial production. Background technique [0002] Protocatechualdehyde (3,4-dihydroxybenzaldehyde) is an important pharmaceutical intermediate, which can enhance hypoxia tolerance, improve renal function, inhibit platelet aggregation, reduce myocardial excitability, relieve chest tightness and angina pectoris in patients with coronary heart disease , to protect the myocardial damage caused by myocardial ischemia and hypoxia and other drug properties, is the active ingredient of inhibitory medicinal compounds; in addition, protocatechuic aldehyde can also be used to synthesize pestic...

Claims

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Application Information

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IPC IPC(8): C07C47/565C07C45/65
Inventor 薛伟周华华
Owner HEBEI UNIV OF TECH
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