Imidazo[1,2‐α]pyrimidines and 1,2,4‐triazolo[1,5‐α]pyrimidines: Two new examples of mesoionic xanthine analogs

Several derivatives of mesoionic imidazo[1,2‐α]pyrimidine‐5,7‐dione and 1,2,4‐triazolo[1,5‐α]pyrimidine‐5,7‐dione, two new examples of mesoionic xanthine ring systems, were prepared and characterized. These compounds were conveniently prepared by the condensation of bis‐(2,4,6‐trichlorophenyl) malonates with the appropriately substituted alkylaminoimiazole or 1,2,4‐triazole.