title: 1,3-Dipolar character of 2-vinyl quinazoline 3-oxides; first and second generation cycloaddition products.
abstract: The reaction between the heteroaromatic N-oxides 1a, 1b and 1c with dimethyl acetylenedicarboxylate or methyl propiolate furnishes 1,3-benzodiazepines, the products of ring transformations of primarily formed cycloadducts. The structures of 8a and 10a have been confirmed by X-ray crystallographic analysis. The aldonitrone 1c also reacts with N-methylmaleimide and with phenyl vinyl sulfone to furnish the first examples of primary cycloaddition products from quinazoline 3-oxides.
authors.affiliation: Department of Chemistry, National University of Ireland, Maynooth, Ireland.
authors.forename: Frances
authors.initials: F
authors.lastname: Heaney
authors.forename: Elaine
authors.initials: E
authors.lastname: Lawless
authors.forename: Mary
authors.initials: M
authors.lastname: Mahon
authors.forename: Patrick
authors.initials: P
authors.lastname: McArdle
authors.forename: Desmond
authors.initials: D
authors.lastname: Cunningham
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D015394:Molecular Structure; D010087:Oxides / Q000138:chemical synthesis / Q000737:chemistry*; D011799:Quinazolines / Q000138:chemical synthesis / Q000737:chemistry*; D014753:Vinyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D010087:Oxides; D011799:Quinazolines; D014753:Vinyl Compounds