PROCESS FOR PREPARATION OF 2,3,5-TRIMETHYLHYDROQUINONE Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: 2,3,5- trimethylhydroquinone is prepared from 3-nitro-o-xylene by reducing 3-nitro-o-xylene to 2,3-xylidine on catalyst containing iron and chromium oxides or active aluminium oxide promoted by alkali and alkaline-earth metal ions. Reducing agent includes C₁-C₃ primary alcohols at 320-350 C and atmospheric pressure. The resulting 2,3-xylidine is subsequently diazotized to 2,3-xylenol, the latter is methylated in vapor phase with methanol over the same catalyst, and the resulting 2,3,6-trimethylphenol is oxidized to 2,3,5-trimethylhydroquinone by chemical or electrochemical methods. EFFECT: more efficient preparation process. 10 ex