SYNTHESIS OF 2-SUBSTITUTED OXAZOLOQUINAZOLINONES

Abstract

The reaction of methyl 2-isothiocyanatobenzoate and 1-azido-3-(4-substituted phenyl)propan-2-ones in the presence of triphenyl phosphine in dioxane by heating produced tricyclic (Z)-2-(4-substituted benzylidene)-2,3-dihydro-5H-oxazolo[2,3-b]quinazolin-5-ones instead of the expected methyl 2-{[5-(4-substituted benzyl)oxazol-2-yl]amino}benzoates. A one-pot procedure for the synthesis of 2-substituted 5H-oxazolo[2,3-b]quinazolin-5-ones from appropriate azidomethyl ketones and 2-isothiocyanatobenzoate was developed.