Method for synthesizing vanillin by using glyoxylic acid and guaiacol together

A technology of guaiacol and glyoxylic acid, applied in the field of medicine and chemical industry, can solve the problems of huge investment in production equipment, long process flow, high cost of raw materials and environmental protection costs, reduce production costs, simplify production processes, and improve the utilization of raw materials. rate effect

Inactive Publication Date: 2011-05-04
TIANJIN VOCATIONAL INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

(Ethyl)vanillin production has problems such as long process flow, huge investment in production equipment, high raw material cost and environmental protection cost.

Method used

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  • Method for synthesizing vanillin by using glyoxylic acid and guaiacol together
  • Method for synthesizing vanillin by using glyoxylic acid and guaiacol together

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Catalyst preparation: Weigh 7.5g (0.03mol) of reagent copper sulfate, 3.4g (0.02mol) of reagent manganese sulfate and 2.4g (0.01mol) of reagent cobalt sulfate, and dissolve them in 100m deionized water to prepare a metal salt solution. Y-type molecular sieve (benzene absorption ≥ 230mg / g; mechanical strength ≥ 80%; SiO 2 / Al 2 o 3 ≥4.5) 100g is added to the above metal salt solution and soaked for 30 minutes, add 5% sodium hydroxide solution to pH11, vacuum filter and separate molecular sieve, wash with a small amount of deionized water, dry at 105°C, and oxidize in a high-temperature furnace at 550°C Bake for 60 minutes and set aside.

[0033] Synthesis of vanillin: Install a 1000mL four-necked reaction bottle equipped with an air distributor, reflux condenser, stirrer and three constant pressure dropping funnels on a constant temperature water bath, and add 74.1g (0.4mol) 40% glyoxylic acid, 59.5g (0.48mol) guaiacol and 100mL 30% liquid caustic soda. Add 500 mL of...

Embodiment 2

[0036] 74.1g (0.4mol) of 40% glyoxylic acid, 52.1g (0.42mol) of guaiacol and 100mL of 30% liquid caustic soda were respectively added to the three constant pressure dropping funnels of the reactor of Example 1. Add 500 mL of deionized water and 106.6 g (0.8 mol) of 30% liquid caustic soda into a four-necked reaction flask, and add 5.0 g of the catalyst prepared in Example 1, stir and blow in air, and the air pressure is 0.05 Mpa. After the solution was heated to 80°C, glyoxylic acid, guaiacol and alkali solution were added dropwise to the reaction flask simultaneously, the dropping speed of glyoxylic acid and guaiacol was controlled at 10mL / h, and the 3-methoxy The concentration of the base-4-hydroxymandelic acid intermediate is less than 2.0%, and the dropping speed of the alkali solution is controlled to make the pH of the solution 11-13. The raw material solution was dropped in about 6 hours, then the temperature was raised to 100° C., stirring was continued and air was blo...

Embodiment 3

[0039] 74.1g (0.4mol) of 40% glyoxylic acid, 52.1g (0.42mol) of guaiacol and 100mL of 30% liquid caustic soda were respectively added to the three constant pressure dropping funnels of the reactor of Example 1. Add 500 mL of deionized water and 106.6 g (0.8 mol) of 30% liquid caustic soda into a four-necked reaction flask, and add 5.0 g of the catalyst prepared in Example 1, stir and blow in air, and the air pressure is normal pressure. After the solution was heated to 80°C, glyoxylic acid, guaiacol and alkali solution were added dropwise to the reaction flask simultaneously, the dropping speed of glyoxylic acid and guaiacol was controlled at 10mL / h, and the 3-methoxy The concentration of the base-4-hydroxymandelic acid intermediate is less than 2.0%, and the dropping speed of the alkali solution is controlled to make the pH of the solution 11-13. The raw material solution was dropped in about 10 hours, then the temperature was raised to 100° C., the stirring and air blowing w...

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Abstract

The invention discloses a method for synthesizing (ethyl) vanillin by using condensation, oxidation and decarboxylation reactions of glyoxylic acid and (ethyl) guaiacol. The method is characterized in that: a Y-shaped molecular sieve is used for loading copper, manganese and cobalt mixed oxide catalysts, and the condensation reaction and the oxidation reaction are simultaneously performed in a reactor. A molar ratio of the glyoxylic acid and the (ethyl) guaiacol serving as raw materials to sodium hydroxide is 1:(1.0-1.2):(2-4); the pH of solution is more than 12 by controlling the dropping speed of alkali solution; and the temperature in the reaction process is controlled to be between 40 and 80 DEG C when the raw materials are dropped, and the temperature in the reaction process is controlled to be between 80 and 100 DEG C after the raw materials are added. The acid concentration of 3-alkoxy-4-hydroxy phenethyl alcohol is below 4 percent all the time during the oxidation reaction. White (ethyl) vanillin crystals are obtained by performing acidification decarboxylation, extraction separation, and vacuum distillation refining on a reaction completing fluid with 50 percent of sulfuric acid, and the yield is 86.3 percent. By the method, an (ethyl) vanillin synthesis process is simplified, the equipment production capacity is improved, and polymerization by-products are restrained, and auxiliary raw material consumption and waste liquid are reduced.

Description

technical field [0001] The invention relates to a method for synthesizing (ethyl) vanillin by using glyoxylic acid and (ethyl) guaiacol through condensation, oxidation and decarboxylation reactions, especially the simultaneous condensation reaction and oxidation reaction in a reactor The invention relates to a method for synthesizing (ethyl) vanillin in one pot without separating intermediate products, and belongs to the field of medicine and chemical industry. Background technique [0002] Vanillin (English name Vanillin), chemical name 3-methoxy-4-hydroxybenzaldehyde, chemical formula C 8 h 8 o 3 , Molecular weight 152.2, white needle crystal, melting point 81-83 ℃, boiling point 284 ℃, slightly soluble in water, soluble in ethanol and chloroform, with vanilla aroma and strong milky aroma. The quality specifications of industrial products are as follows: [0003] project indicators Exterior White to light yellow needle-like crystalline powder ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C47/58C07C47/575C07C45/65B01J29/16
Inventor 李建生李霞刘炳光
Owner TIANJIN VOCATIONAL INST
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