The synthesis of imidazo[4,5‐c]‐, <i>s</i>‐triazolo[4,3‐b]‐, and tetrazolo[1,5‐b]pyridazines

Abstract

Abstract The adenine analog, 7‐aminoimidazo[4,5‐c]pyridazine (XII) and three other members of this previously unknown ring system have been prepared. The adenine analog, 8‐amino‐tetrazolo[1,5‐b]pyridazine (I) has also been prepared together with three other compounds in this ring system. The novel displacement of halogen in nitrogen heterocycles with phosphorus pentasulfide has been extended.