The PIFA-initiated oxidative cyclization of 2-(3-butenyl)quinazolin-4(3 H )-ones - an efficient approach to 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2- a ]quinazolin-5(1 H )-ones

A regioselective method for the synthesis of 1-(hydroxymethyl)-2,3-dihydropyrrolo[1,2- ]quinazolin-5(1 )-ones - close structural analogs of naturally occurring vasicinone alkaloids - is described. The procedure is based on PIFA-initiated oxidative 5- cyclization of 2-(3-butenyl)quinazolin-4(3 )-ones, in turn prepared by thermal cyclocondensation of the corresponding 2-(pent-4-enamido)benzamides. The products obtained have a good natural product likeness (NPL) score and therefore can be useful for the design of natural product-like compound libraries.