2-Methylresorcinol CAS 608-25-3

Using glutaric acid as the initial raw material, under the catalysis of nitrobenzene and aluminum chloride, it reacts with acetyl chloride to generate 2-methyl-1,3-cyclohexanedione, 2-methyl-1,3-cyclohexane The target product 2,6-dihydroxytoluene can be obtained by reacting hexanedione with acetic anhydride and then hydrolyzing it.

CAUTION: The acetic anhydride vapor used in this route is toxic, so great care needs to be taken when experimenting. Moreover, this synthetic route is relatively complicated and requires three-step reactions to complete, which will produce more by-products, which is inconvenient for the separation and purification of products, making the post-treatment relatively complicated, and the pollution to the environment is also serious, and the reaction conditions are difficult. Control, the total recovery is about 50%.

Using p-toluic acid as raw material, after sulfonation reaction, hydrolysis under the condition of strong alkali NaOH and KOH, the generated salt is acidified with hydrochloric acid, and finally decarboxylated under the condition of nitrobenzene to obtain the target product.

The synthesis route undergoes three-step reactions. The first two steps require the use of a large amount of strong acids and bases such as sulfuric acid, hydrochloric acid, sodium hydroxide, and potassium hydroxide. It will become serious, which is not in line with the principles of green chemistry. This reaction causes the total yield of target product to be relatively low owing to many steps are complicated in operation in addition, can only reach about 50%.

1,3-Cyclohexanedione reacts with the aqueous solution of dimethylamine and the formaldehyde solution in the methanol medium, then transfers to the autoclave to carry out the hydrogenation reaction under the catalysis of palladium carbon to generate the intermediate 2-methyl-1, 3-cyclohexanedione and then 2-methyl-1,3-cyclohexanedione are dehydrogenated in mesitylene under reflux to obtain the product 2,6-dihydroxytoluene.

This method is divided into two steps. First, 2,6-dinitrotoluene is used for hydrogenation reaction under high temperature and high pressure conditions, and then under acetic acid system, palladium carbon is used as a catalyst, and 2,6-dinitrotoluene is hydrolyzed under high temperature and high pressure conditions to obtain 2,6- Dihydroxytoluene.