In step (10) of Reaction Scheme I, a 1H-imidazo[4,5-c][1,5]naphthyridine-5N-oxide or 1H-imidazo[4,5-c]quinoline-5N-oxide of Formula XXIV is aminated to provide a 1H-imidazo[4,5-c][1,5]naphthyridin-4-amine or 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXV. Step (10) involves the activation of an N-oxide of Formula XXIV by conversion to an ester and then reacting the ester with an aminating agent. Suitable activating agents include alkyl- or arylsulfonyl chlorides such as benzenesulfonyl chloride, methanesulfonyl chloride, or p-toluenesulfonyl chloride. Suitable aminating agents include ammonia, in the form of ammonium hydroxide, for example, and ammonium salts such as ammonium carbonate, ammonium bicarbonate, and ammonium phosphate. The reaction is conveniently carried out by adding ammonium hydroxide to a solution of the N-oxide of Formula XXIV in a suitable solvent such as dichloromethane or chloroform and then adding p-toluenesulfonyl chloride. The reaction can be carried out at ambient temperature. Under these reaction conditions, the N-phthalimide protecting group is removed to provide the 1H-imidazo[4,5-c][1,5]naphthyridin-4-amine or 1H-imidazo[4,5-c]quinolin-4-amine of Formula XXV or a pharmaceutically acceptable salt thereof, which can be isolated from the reaction mixture using conventional methods.
