Studies of polyazapentalenes. I. The preparation of 6-dehydroindazolo[1,2-a]benzotriazole

The photolysis of 1-(o-azidophenyl)-1H-indazole (IV) has been found to give a mix ture of 6-dehydroindazolo1,2-a]benzolriazole (VI) and 2,2′-di(1-indazolyl)azobenzene (VII). On the other hand, 1-(o-nilrophenyl)-1H-indazole (1) was reduced with triethyl phosphite, affording VI and dibenzoa,i] indazolo1,2,′3-cd] indazolo3,2,1-fg]-3,3a,5a,6,8a,8b-hexaaza-as-indacene (XIa).