Condensation between 3-amino-6-chloropyridazine (I) and 3-hydroxy-2-methylpyridine (II) in aqueous NaOH at 175 C under pressure afforded the bisaryl ether (III). The phenyl carbamate (IV) was then prepared by treatment of aminopyridazine (III) with phenyl chloroformate. Finally, coupling of carbamate (IV) with 6-chloro-5-methylindoline (V) yielded the title urea derivative.