The final step in the synthesis of the natural bioantioxidant echinochrome (1), the active principle of the drug HistochromTM [1], is demethylation of its trimethyl ether 2 [2, 3]. This process is known to occur through the action of anhydrous AlCl3 in nitrobenzene [2] or with prolonged boiling of 2 in ethanol: HCl (conc.)[4].
