0.03 mole (4.56 g) of 3-ureido phenol is dissolved in 100 cc of isopropyl alcohol to which have been added 100 cc of ammonia at 22° Be. 350 g of crushed ice are then added to this solution. The resulting reaction mixture is maintained at about 0° C., and there are introduced simultaneously, with good agitation and with the aid of a double funnel, 0.03 mole (6.27 g) of the dihydrochloride of N,N-dimethyl paraphenylenediamine in 50 cc of water and 0.060 mole (13.7 g) of ammonium persulfate in 50 cc of water. At the end of this addition, the agitation is continued for 15 minutes and the above indoaniline which has precipitated is then filtered, washed with water, recrystallized in a mixture of dimethylformamide in water and dried under a vacuum. It exhibits a melting point of 226° C.
