Approach to the Synthesis of 2,3-Disubstituted-3H-quinazolin-4-ones Mediated by Ph3P-I2.

Readily available N-substituted amides or their requisite carboxylic acids or acid chlorides have been used to construct 2,3-disubstituted-3H-quinazolin-4-ones in a one-pot procedure. Key transformation in this convergent approach involves Ph3P-I2-mediated formation of amidine upon condensation of an amide or the intermediate amide with methyl anthranilate. Cyclization of the amidine-tethered anthranilate then affords 2,3-disubstituted-3H-quinazolin-4-ones in good to excellent yields under mild conditions.