Pteridin-4(3H )-ones and related compounds: synthesis via intermolecular aza-Wittig reaction–heterocyclization and crystal structure

2,3-Disubstituted pteridin-4(3H)-one derivatives have been synthesized by the intermolecular aza-Wittig reaction–heterocyclization methodology. The structures of 3-allyl-2-anilinopteridin-4(3H)-one and 2-anilino-3-isopropylpteridin-4(3H)-one were determined by X-ray crystallographic analysis. Furthermore, imidazo[2,1-b]pteridine derivatives were synthesized by heterocyclization including iodoamination.