Method for producing guaiacol with methanol method

Abstract

The invention provides a method for preparing guaiacol by a methanol method. Methanol used as a methylating agent and pyrocatechol are used for synthesizing the guaiacol under the action of a solid acid catalyst in a high pressure vessel. The solid acid catalyst used for synthesizing the guaiacol has low price, is friendly to environment and can be recycled. The invention is characterized in that the invention has simple preparation technology, mild reaction condition and short reaction time; the obtained guaiacol is light yellow clear transparent liquid and has good product quality, high yield, high selectivity and few side products; and all side products in reaction liquid can be recycled.

Description

technical field [0001] The invention relates to the technical field of organic chemical synthesis, in particular to a method for preparing guaiacol by catalyzing a solid acid catalyst. technical background [0002] Guaiacol, also known as o-methoxyphenol or o-hydroxyanisole, is an important fine chemical intermediate widely used in the synthesis of medicine, spices and dyes, especially in the synthesis of vanillin ). There are only a small number of manufacturers in Jilin, Shanghai, Jiangsu and other places in China, which cannot meet the growing demand. According to the synthetic raw materials, there are three main synthetic methods of guaiacol: (1) it is obtained by diazotization and hydrolysis of o-aminoanisole; (2) it is obtained by catechol and methyl iodide under the action of NaOH Obtained; (3) synthesize guaiacol under the action of catalyst with ortho-chlorophenol as raw material; (4) carry out hydroxyl oxygen monoetherification reaction with catechol, dimethyl su...

AI Technical Summary

Problems solved by technology

There are only a small number of manufacturers in Jilin, Shanghai, Jiangsu and other places in China, which cannot meet the growing demand

According to the synthetic raw materials, there are three main synthetic methods of guaiacol: (1) it is obtained by diazotization and hydrolysis of o-aminoanisole; (2) it is obtained by catechol and methyl iodide under the action of NaOH Obtained; (3) synthesize guaiacol under the action of catalyst with ortho-chlorophenol as raw material; (4) carry out hydroxyl oxygen monoetherification reaction with catechol, dimethyl sulfate and dimethyl carbonate to obtain guaiacol Wood phenol; (5) with methyl chloride and catechol as raw materials, phase transfer catalyst catalyzed this reaction yield is higher as 80% (Li Depeng etc., the synthetic research of guaiacol. Jiangsu Chemical Industry, 1998,26 (5 ), 18-20), but the preparation process is complicated, and there is an excessive amount of methyl chloride gas polluting the environment

In view of the deficiencies of the above-mentioned various methods, in the recent research work on the alkylation of phenols, a new guaiacol synthesis process has aroused people's strong interest. This method uses methanol and catechol in a fixed-bed reactor Carry out gas-phase reaction (Xu Yan, Fu Zaihui, etc., ZnCl2 / NaY catalyzed the etherification reaction of catechol and methanol. Applied Chemistry, 2004, 21 (7), 664-668), obtain guaiacol under the action of catalyst The yield is higher than 80%, but the catalyst preparation process is complex, the catalyst calcination temperature is high, and the catalyst recycling efficiency is not high; in addition, at a reaction temperature of 280 ° C, there are many series and parallel side reactions in the catalytic reaction process compared with traditional catalysts Occurrence, generate a variety of by-products (such as o-dimethoxybenzene, methyl catechol, methyl guaiacol, etc.), which will cause carbon deposition on the catalyst during the reaction and reduce the catalytic activity

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