Synthesis of novel 4H-pyrimido[1,6-a]pyrimidines via a one-pot three-component condensation

Highly substituted novel 4H-pyrimido[1,6-a] pyrimidines were prepared by a trifluoromethanesulfonic acid catalyzed one-pot three-component condensation of 4-aminopyrimidines, aldehydes, and beta-ketoesters. A preliminary feasibility study was undertaken on these compounds, to assess the potential production of a library of further diversified compounds by nucleophilic replacement of Cl (R-1) or by reaction of electrophiles with the NH2 (R-2) group.