Nitric Acid → 2,5-Cyclohexadiene-1,4-dione, 2,3,5-trimethyl-

Participants

Reaction Steps

13.6 g (0.1 mole) of 2,3,6-trimethylphenol was dissolved in 100 g of acetic acid, and 7.4 g (0.104 mole) of chlorine gas bubbled thereinto at 20° - 30°C under stirring. Gas chromatography at this stage showed that p-chloro derivative was produced fairly quantitatively. 10 g of commercially available concentrated nitric acid (63 percent) was added dropwise thereto in 30 minutes without removing acetic acid. The temperature rose to 30°C. After dropwise addition, the stirring was continued for another 30 minutes, and then the reaction solution was subjected to steam distillation. The steam distillation was discontinued at the time when the yellow color of the distillate disappeared, and the distillate was extracted with ether. The ether layer was washed with an aqueous solution of sodium bicarbonate and dried over sodium sulfate (anhydrous), followed by distillating off ether. Thus, there was obtained 13.5 g (90 percent in yield) of 2,3,6-trimethyl-p-benzoquinone.

Provenance & Evidence