A new effective method for the synthesis of imidazo[1,5-b]pyridazines derivatives (yields = 68-89%) by the interaction of 1,2-diamino-4-phenylimidazole with DMAD, in methanol and in the presence of a catalytic amount of acetic acid, is proposed. The course of reaction has been examined by classical organic methods, HPLC-MS analysis, and quantum-chemical calculations.
Keywords: DFT calculations; dimethyl acetylenedicarboxylate; imidazo[1,5-b]pyridazines.