Synthesis of Isoxazolopyridazin-4(5H)-ones and 4-Acyl-5-hydroxy-3(2H)-pyridazinones
The title compounds were prepared from ethyl 5-acyl- or 5-(1-hydroxyethenyl)isoxazole-4-carboxylates which in turn were prepared from ethyl 3-methylamino-2-butenoate or 3(2H)-furanones.