Synthesis and antifungal activity of imidazo[1,2-b]pyridazine derivatives against phytopathogenic fungi

•Some novel 3,6-disubstituted imidazo[1,2-b]pyridazine derivatives were prepared.•This is the first report on the antifungal activity against plant pathogens of imidazo[1,2-b]pyridazine skeleton.•Compounds 4a, 4c, 4d, 4l and 4r exhibited more potent antifungal activities compared with the two positive controls hymexazol and carbendazim.