7-Deazapurines: Synthesis of new pyrrolo[2,3-d]pyrimidin-4-ones catalyzed by a Brønsted-acidic ionic liquid as a green and reusable catalyst

Some new 2-aryl-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-ones have been prepared through cyclocondensation of 2-amino-1H-pyrrole-3-carboxamides with aromatic aldehydes followed by air oxidation in the presence of 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate [(CH2)4SO3HMIM][HSO4], a Brønsted-acidic ionic liquid, as a green and reusable catalyst in solvent-free conditions.