title: Synthesis of unsymmetrical 3,3'-biquinazoline-2,2'-diones by condensation of 3-aminoquinazolinones with benzoxazinones; fortuitous discovery, and further syntheses of 4-H-3-oxo-1,9a,10-triazaanthracen-9-ones.
abstract: Condensation of 2-alkyl- or 2-aryl-3-aminoquinazolin-4-ones with benz[1,3]oxazin-4-ones gives the unsymmetrical 2,2' disubstituted 3,3' biquinazoline-4,4'-diones. The reaction is tolerant to a range of heteroatom and unsaturated functionality in the quinazolinone 2-position. However, treatment of 3-amino-2-hydroxymethyl-3H-quinazolin-4-ones with benz[1,3]oxazinone at high temperatures gave 4H-3-oxo-1,9a,10-triazaanthracen-9-ones, an unreported fused heterocyclic system, a more direct synthesis of which, replacing benzoxazinones with orthoesters is presented.
authors.affiliation: Department of Chemistry, Cardiff University, Park Place, Cardiff, Wales (Cymru) CF10 3TB, UK. cooganmp@cf.ac.uk
authors.forename: Michael P
authors.initials: MP
authors.lastname: Coogan
authors.forename: Li-ling
authors.initials: LL
authors.lastname: Ooi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Pertusati