Method of preparing methyl catechol using calcium nitrite as raw material

Abstract

The present invention relates to a method for preparing guaiacol by using calcium nitrite as raw material. Said method is characterized by that it includes the following steps: in a diazotization still adding o-aminoanisole into dilute sulfuric acid to make neutralization to obtain methyl ether sulfate, then drop-adding calcium nitrite solution to make diazotization reaction, separating out solid residue, feeding the diazotization solution into hydrolysis procedure to make hydrolysis reaction so as to obtain crude guaiacol, then feeding the obtained crude guaiacol into separation procedure; making the waste liquor be fed into copper sulfate recovery procedure and making the phenol water containing crude guaiacol be fed into phenol recovery procedure, making the phenol water be continuously adsorbed in adsorption tower with macroporous adsorbing resin, using sodium hydroxide solution to make elution, using sulfuric acid to acidify eluent to separate out crude guaiacol; mixing above-mentioned two crude guaiacols in a distillation still, making reduced pressure distillation to remove water content and impurity from crude guaiacol so as to obtain the invented guaiacol finished product.

Description

technical field [0001] The invention relates to the field of chemistry, and relates to a method for preparing guaiacol by using calcium nitrite as a raw material. Guaiacol is mainly used in the pharmaceutical industry to produce calcium guaiacol sulfonate; in the fragrance industry to produce vanillin and artificial musk. Background technique [0002] The preparation method of existing guaiacol comprises the following steps: a diazotization process, diazotization process is to use sodium nitrite and anthranil as raw materials, carry out low-temperature diazotization reaction under acidic conditions, generate A diazonium solution composed of anthranilic ether diazonium salt and sodium sulfate; b hydrolysis process, the hydrolysis process is to hydrolyze the diazo solution under the catalysis of copper sulfate to generate guaiacol and sulfuric acid, and release nitrogen , guaiacol is carried out by water vapor in the form of water vapor distillation; c s...

AI Technical Summary

Problems solved by technology

[0003] The weak point of the preparation method of existing guaiacol is: 1. in hydrolysis process, along with the increase of reaction generation sulfuric acid amount, the sodium sulfate that generates in the diazo process forms mixed crystal and separates out gradually with catalyzer copper sulfate, makes The catalytic effect of copper sulfate is gradually reduced, which affects the hydrolysis yield; 2. It is difficult to separate the copper sulfate in the large-scale waste liquid from the generated sodium sulfate, and it needs to be converted into copper or copper oxide for recovery. The operating cost is high, and a large amount is difficult to handle 0.5-0.6 tons of copper sulfate per ton of guaiacol; 3. The phenolic water produced by hydrolysis is extracted with benzene to dissolve the dissolved guaiacol, and each ton of guaiacol needs to consume 0.05-0.08 tons of benzene, and consume 8-10 tons of steam to recover the solvent. The raffinate phase after benzene extraction contains benzene and other organic matter with a high COD value of 2000-4000 mg / L, and each ton of guaiacol produces 10-10 tons of waste water. 12 tons, high processing costs

Images