title: Radical reactions with 3H-quinazolin-4-ones: synthesis of deoxyvasicinone, mackinazolinone, luotonin A, rutaecarpine and tryptanthrin.
abstract: Alkyl, aryl, heteroaryl and acyl radicals have been cyclised onto the 2-position of 3H-quinazolin-4-one. The side chains containing the radical precursors were attached to the nitrogen atom in the 3-position. The cyclisations take place by aromatic homolytic substitution hence retain the aromaticity of the 3H-quinazolin-4-one ring. The highest yields were obtained using hexamethylditin to facilitate cyclisation rather than reduction without cyclisation. The alkaloids deoxyvasicinone , mackinazolinone , tryptanthrin , luotonin A and rutaecarpine were synthesised by radical cyclisation onto 3H-quinazolin-4-one.
authors.affiliation: Department of Chemistry, Loughborough University, Loughborough, Leics, UK.
authors.forename: W Russell
authors.initials: WR
authors.lastname: Bowman
authors.forename: Mark R J
authors.initials: MR
authors.lastname: Elsegood
authors.forename: Tobias
authors.initials: T
authors.lastname: Stein
authors.forename: George W
authors.initials: GW
authors.lastname: Weaver
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D005609:Free Radicals / Q000737:chemistry; D026121:Indole Alkaloids; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D011799:Quinazolines / Q000138:chemical synthesis* / Q000737:chemistry; D052999:Quinazolinones; D011809:Quinones / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000470:Alkaloids; D005609:Free Radicals; D026121:Indole Alkaloids; D011758:Pyrroles; D011799:Quinazolines; D052999:Quinazolinones; D011809:Quinones; C480761:luotonin A; C510340:mackinazolinone; C046243:tryptanthrine; C025696:2,3-trimethylene-4-quinazolone; C028632:rutecarpine