3-Trifluoromethyl-4-nitrophenylisocyanate (I) and 2-amino-2-cyanopropane (II) are condensed. After concentration by distillation under reduced pressure and chromatography of the residue on silica gel (elution with dichloromethane: acetone, 8:2 v/v), the intermediate 1-(3'-trifluoromethyl-4'-nitrophenyl)-4,4-dimethyl-5-imino-2-imidazolidinone) (III) is obtained. This intermediate, in suspension in aqueous hydrochloric acid, is heated, then cooled and poured into water. The precipitate, filtered, washed and dried, is anandron (RU-23908), which can be recrystallized in an ethanolic medium.

3-Trifluoromethyl-4-nitrophenylisocyanate (I) and 2-amino-2-cyanopropane (II) are condensed. After concentration by distillation under reduced pressure and chromatography of the residue on silica gel (elution with dichloromethane: acetone, 8:2 v/v), the intermediate 1-(3'-trifluoromethyl-4'-nitrophenyl)-4,4-dimethyl-5-imino-2-imidazolidinone) (III) is obtained. This intermediate, in suspension in aqueous hydrochloric acid, is heated, then cooled and poured into water. The precipitate, filtered, washed and dried, is anandron (RU-23908), which can be recrystallized in an ethanolic medium.