Reaction of 2-Hydroxy-5-methylacetophenone Chalcones with Guanidine in the Presence of Hydrogen Peroxide

Two chalcones derived from 2-hydroxy-5-methylacetophenone reacted with guanidine in the presence of hydrogen peroxide to give 4,6-diaryl-2-aminopyrimidine or flavonol derivative, depending on the initial chalcone structure. The products were identified by NMR spectroscopy and X-ray analysis. Probable reaction paths were proposed.