Synthesis of a Novel Hexa Cyclic Benzimidazo[1,2-c]indazolo-[2,3-a]quinazoline

The Conversion of 4-Anilinoquinazoline- and 3-Aryl-4-imino-3,4-dihydro-quinazoline-2-carbonitriles into Benzo[4,5]imidazo[1,2-c]quinazoline-6-carbonitriles via Oxidative and Nonoxidative C–N Couplings

“…These metal free conditions worked well for the parent, the 4-Me and the 4-MeO substituted analogues (Table 1, entries 1-3), however, the reactions with 4-anilinoquinazolines that hosted inductively electron withdrawing halogen substituents on the aniline moiety (Table 1, entries [6][7][8][9][10][11][12][13][14][15][16][17] required prolonged reaction times. As such, we re-optimized the reaction conditions Table 1.…”

“…Most syntheses of benzo­[4,5]­imidazo­[1,2- c ]­quinazolines focus on building the pyrimidine ring starting from 2-(2-aminophenyl)­benzimidazoles 2 ,,,, or via structurally related precursors, e.g., 2-(2-nitrophenyl)­benzimidazoles, N -[2-(benzimidazol-2-yl)­phenyl]­phosphanimines, 2-(2-azidophenyl)­benzimidazoles, N -[2-(benzimidazol-2-yl)­phenyl]­methanimines, ,, and 2-(2-halophenyl)­benzimidaz-oles . A second major synthetic route of benzo­[4,5]­imidazo­[1,2- c ]­quinazolines is via construction of the imidazole ring which has been limited to treatment of 4 H -benzo­[ d ]­[1,3]­oxazin-4-ones 3 with 1,2-benzenediamines either directly ,,,,, or via the isolable intermediate 3-(2-aminophenyl)-3 H -quinazolin-4-ones , or structurally related benzo­[1,3]­thiazin-4-ones …”