title: Novel synthesis of cinnolines and 1-aminoindolines via Cu-catalyzed intramolecular N-arylation of hydrazines and hydrazones prepared from 3-haloaryl-3-hydroxy-2-diazopropanoates.
abstract: A new and facile access to cinnolines, dihydrocinnolines, and 1-aminoindolines was established by use of diazo functionalities. The hydrazines and hydrazones as cyclization precursors derived from 3-haloaryl-3-hydroxy-2-diazopropanoates, which are prepared by one-pot procedure utilizing phase-transfer catalysis, are successfully converted to the corresponding nitrogen heterocycle by Cu-catalyzed N-arylation. Furthermore, analysis of UV spectra proved that 4-oxo-3-carboxylates predominantly exist not as 4-hydroxycinnoline (enol form) but as cinnolone (keto form).
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Kimura
authors.forename: Shigeru
authors.initials: S
authors.lastname: Arai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nishida
mesh_terms: D000588:Amines / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D006574:Heterocyclic Compounds, 2-Ring / Q000138:chemical synthesis*; D006834:Hydrazines / Q000138:chemical synthesis / Q000737:chemistry*; D006835:Hydrazones / Q000138:chemical synthesis / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D011422:Propionates / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000588:Amines; D006574:Heterocyclic Compounds, 2-Ring; D006834:Hydrazines; D006835:Hydrazones; D007211:Indoles; D011422:Propionates; C057812:indoline; D003300:Copper; C476282:cinnoline