title: An I2-mediated cascade reaction of 2'-bromoacetophenones with benzohydrazides/benzamides leading to quinazolino[3,2-b]cinnoline or tryptanthrin derivatives.
abstract: An efficient and facile protocol for the synthesis of quinazolinone-fused tetracyclic compounds through an iodine-mediated one-pot cascade reaction of 2'-bromoacetophenones with 2-aminobenzohydrazides or 2-aminobenzamides is reported. With 2-aminobenzohydrazides as the substrates, the reaction gave 5H-quinazolino[3,2-b]cinnoline-7,13-diones in moderate to good yields under metal-catalyst-free conditions. With 2-aminobenzamides as the substrates and CuBr as the catalyst, on the other hand, it afforded tryptanthrin derivatives with good efficiency. Mechanistically, the formation of the tetracyclic systems is initiated by iodination and oxidation of 2'-bromoacetophenones followed by a cascade procedure consisting of cyclocondensation, aromatization and intramolecular cyclization of the in situ formed 2-bromoarylglyoxals with 2-aminobenzohydrazides or 2-aminobenzamides, respectively.
authors.affiliation: Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China. shguo@htu.cn xuesen.fan@htu.cn.
authors.forename: Shenghai
authors.identifier: http://orcid.org/0000-0002-2797-4281
authors.initials: S
authors.lastname: Guo
authors.affiliation: Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China. shguo@htu.cn xuesen.fan@htu.cn.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Zhai
authors.affiliation: Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China. shguo@htu.cn xuesen.fan@htu.cn.
authors.forename: Xuesen
authors.identifier: http://orcid.org/0000-0002-2040-6919
authors.initials: X
authors.lastname: Fan
mesh_terms: D000098:Acetophenones / Q000737:chemistry*; D001549:Benzamides / Q000737:chemistry*; D006574:Heterocyclic Compounds, 2-Ring / Q000138:chemical synthesis* / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry*; D015394:Molecular Structure; D011799:Quinazolines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000098:Acetophenones; D001549:Benzamides; D006574:Heterocyclic Compounds, 2-Ring; D006834:Hydrazines; D011799:Quinazolines; C046243:tryptanthrine; D007455:Iodine; C006712:benzoylhydrazine; C476282:cinnoline