To a solution of 0.003 mol of N-methyl-N-isopropyl-4-aminoaniline hydrochloride and 0.003 mol of 4-butoxybenzene-1,3-diamine dihydrochloride in 2 ml of water and 6 ml of ethanol, brought to pH 9.5 with 20% aqueous ammonia solution, are added 10.2 ml of 20-V 6% aqueous hydrogen peroxide solution; after stirring for 24 hours at room temperature, a gum forms. The supernatant is removed and the gum is washed with three times 50 ml of water, 4 ml of ethyl acetate and then with isopropyl ether. After drying, 260 mg of 4-butoxy-6-[4-(ethylisopropylamino)phenylamino]-3-iminocyclohexa-1,4-dienylamine hydrochloride 1 are obtained in the form of a black powder.
