Method for preparing 3,4-dimethoxy toluene under catalysis

Abstract

The invention provides a method for preparing 3,4-dimethoxy toluene, which comprises the following steps of: alkalizing 4-methyl guaiacol with corresponding molar weight by using aqueous solution of inorganic alkali at certain concentration; heating alkalized 4-methyl guaiacol solution with stirring to the temperature of between 60 and 150 DEG C; and introducing monohalomethane into reaction liquid, reacting at the temperature of between 60 and 150 DEG C, cooling the reaction liquid after the reaction is finished, and directly separating to obtain a target product, namely the 3,4-dimethoxy toluene. The reaction speed and the yield of the product can be improved by adding an appropriate catalyst into the reaction liquid. The method for preparing the 3,4-dimethoxy toluene has the advantages of high selectivity and yield of the target product, and the like; in addition, the method is simple and has low cost and good application prospect.

Description

【Technical field】 [0001] The invention relates to the fields of fine chemical industry and organic synthesis, in particular to a method for catalytically preparing 3,4-dimethoxytoluene. 【Background technique】 [0002] 3,4-Dimethoxytoluene (3,4-Dimethoxytoluene), also known as 1,2-dimethoxy-4-methylbenzene (benzene, 1,2-dimethoxy-4-methyl-) is a synthetic fragrance and It is an important intermediate of pharmaceuticals and has a large market demand. At present, the main ways to catalyze the preparation of 3,4-dimethoxytoluene are: (1) with 3,4-dimethoxybenzyl alcohol, H 2 S and CO as raw materials, in the catalyst Co 2 (CO) 8 Under the action of conversion into 3,4-dimethoxytoluene. This type of reaction needs to be carried out under high temperature and high pressure, the reaction time is long, the product selectivity is poor, and the yield is low; and the poisonous gas H 2 S and CO are used as reaction reagents, which are easy to cause accidents such as poisoning and e...

AI Technical Summary

Problems solved by technology

This type of reaction takes a long time and the separation of products is complicated, so it is not an economical production route

(4) Other catalysts such as CeO 2 , PdCl 2 (PhCN) 2 And Na Hg alloy etc., there are few reports about these catalysts being used to catalyze the preparation of 3,4-dimethoxytoluene;