TETRAHEDRON, cilt.47, sa.4-5, ss.675-684, 1991 (SCI-Expanded)
4-H-Pyrido[1,2-a]pyrimidine-2,4-diones (Chichibabin) derivatives, formed by condensation of 2-aminopyridines with substituted dialkylmalonates, are electroactive. In solution in CH2Cl2/CF3CO2H mixtures they are smoothly and selectively anodically coupled in high yield. The products are novel and unexpected; radical coupling at the C-3 and O-4 positions is involved and the proposed mechanism is analogous to that of oxidative phenolic coupling.