Synthesis of Trimethylhydroquinone

In an attempt to find a new method for the synthesis of trimethyl-hydroquinone (TMH), an intermediate for vitamin E, from pseudocumene (1), the rearrangement of N-(2, 4, 5-trimethylphenyl)hydroxylamine (2) has been studied under various conditions. The hydroxylamine (2), prepared by nitration and partial reduction of (1), was rearranged into TMH in 10% yield on treatment with 10% sulfuric acid at 0-2°C with subsequent heating with 5% sodium hydroxide solution at 90-95°C. Pseudocumoquinol (3), an intermediate for TMH, could be isolated from the reaction mixture in 59% yield when the hydroxylamine (2) was treated with acid. The base-catalyzed rearrangement of (3) gave TMH in 13% yield. In order to clarify the effects of methyl substituents, the rearrangement of other N-(trimethylphenyl)hydroxylamines obtained from mesitylene and hemimellitene was also examined.