Abstract The readily available title compounds 4a and 24 react with N-, O-, S-, and C- nucleophiles in presence of MnO 2 to give the corresponding mono-or disubstituted 2H- azabenzimidazoles (= azaisobenzimidazoles), eg, 11–18 and 26a–h, respectively, or 2, 3- dihydro-1H-azabenzimidazoles (= dihydro-azabenzimidazoles) such as 9 and 10 and 27 and 28, respectively, by a 1, 4-or 1, 6-Michael addition (Schemes 2 and 4). The bromo- ...