title: Quinoxalino[2,3-c]cinnolines and their 5-N-oxide: alkoxylation of methyl-substituted quinoxalino[2,3-c]cinnolines to acetals and orthoesters.
abstract: We report the alkoxylation of methyl-substituted quinoxalino[2,3-c]cinnolines to give acetals and orthoesters in high yields. Routes to the precursors of this alkoxylation reaction as well as other quinoxalino[2,3-c]cinnoline and their 5-oxide derivatives are reported. Most of these quinoxalino[2,3-c]cinnolines were prepared by cyclization of the corresponding 2-amino-3-(2-nitrophenyl)quinoxaline, which, in turn, result from an unusual Beirut reaction from benzofurazan oxides plus 2-nitrobenzylcyanides. Mechanistic explanations for these intriguing reactions are presented.
authors: Department of Chemistry, American University of Beirut, Beirut, Lebanon. haddadin@aub.edu.lb
authors: Makhluf J
authors: MJ
authors: Haddadin
authors: Mirna
authors: M
authors: El-Khatib
authors: Tharallah A
authors: TA
authors: Shoker
authors: Christine M
authors: CM
authors: Beavers
authors: Marilyn M
authors: MM
authors: Olmstead
authors: James C
authors: JC
authors: Fettinger
authors: Kelli M
authors: KM
authors: Farber
authors: Mark J
authors: MJ
authors: Kurth
mesh_terms: D000080:Acetals / Q000737:chemistry; D000438:Alcohols / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000627:therapeutic use; D001583:Benzoxazoles / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003486:Cyanides / Q000737:chemistry; D003500:Cyclization; D004952:Esters / Q000737:chemistry; D006574:Heterocyclic Compounds, 2-Ring / Q000032:analysis / Q000138:chemical synthesis*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009369:Neoplasms / Q000188:drug therapy; D010087:Oxides / Q000737:chemistry; D011810:Quinoxalines / Q000032:analysis / Q000138:chemical synthesis*; D000077704:Tirapazamine; D014227:Triazines / Q000138:chemical synthesis / Q000627:therapeutic use
chemical_list: D000080:Acetals; D000438:Alcohols; D000970:Antineoplastic Agents; D001583:Benzoxazoles; D003486:Cyanides; D004952:Esters; D006574:Heterocyclic Compounds, 2-Ring; D010087:Oxides; D011810:Quinoxalines; D014227:Triazines; C059688:alkoxyl radical; D000077704:Tirapazamine; C020160:benzofurazan; C476282:cinnoline