Productive technology of vanlillin by glyoxylic acid method

Abstract

The invention discloses a productive technology of vanlillin by a glyoxylic acid method. The productive technology comprises a synthesis process, a fractionation process and a purification process, wherein the synthesis process comprises condensation treatment, oxidation treatment and decarboxylation treatment of methyl catechol and glyoxylic acid. The productive technology particularly comprisesthe following steps: respectively converting the methyl catechol and the glyoxylic acid into guaiacol sodium and sodium glyoxylate in a sodium hydroxide system; carrying out condensation treatment onthe guaiacol sodium and the sodium glyoxylate; after recovering the unreacted methyl catechol in a condensation liquid, carrying out oxidation treatment, namely carrying out catalytic oxidation on anethanol group in 4-hydroxy-3-methoxybenzene sodium glycolate by using copper oxide in the sodium hydroxide system to form a ketone group, thereby generating a corresponding ketonic acid compound; after separating red copper oxide particles from an oxidation liquid, carrying out decarboxylation treatment, namely using sulfuric acid to acidize the oxidation liquid, and simultaneously converting an acid group in the ketonic acid compound into carbon dioxide so as to generate 4-hydroxy-3- methoxybenzaldehyde; and carrying out the fractionation process and the purification process to obtain the vanlillin.

Description

technical field [0001] The invention relates to a production process of vanillin, in particular to a glyoxylic acid production process of vanillin. Background technique [0002] The vanillin molecule contains three functional groups: hydroxyl, methoxy and aldehyde, so it is named 4-hydroxy-3-methoxybenzaldehyde. Its structural formula is: [0003] [0004] Due to the hydroxyl group contained in the vanillin molecule, it is weakly acidic in aqueous solution. Vanillin is easily soluble in ethanol, ether, chloroform, glacial acetic acid and hot volatile oil, slightly soluble in water. [0005] Vanillin has sweet, milky and vanilla aroma, and is one of the most important food spices. It is widely used in four aspects: food additives, pharmaceutical intermediates, feed additives and others (such as electroplating brighteners and biochemical reagents, etc.). Additives about 20% and other uses about 10%. In recent years, the application in the field of medicine has been con...

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Problems solved by technology

[0007] The technical problem to be solved by this invention is to eliminate the p-nitroso N,N-dimethylaniline hydrochloride in the traditional formaldehyde synthesis and avoid the toxic benzene produced in the condensation process. For purposes such as reducing environmental pollution, simplifying the process, and improving yield, a glyoxylic acid production process of vanillin is provided

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