Directfunctionalization of 4,5-dichloropyridazin-6-one with some nucleophiles in seven solvents gave regioselectively 5-halo-4-substituted-pyridazin-6-ones as main product. Reaction of 4,5-dichloropyridazin-6-one with 2-mercaptopyrimidine (2 equivalents) also afforded 4,5-di(pyrimidin-2-ylsulfanyl)pyridazin-6-one as the main product.
Functionalization of 1-hydroxymethyl-4,5-dihalopyridazin-6-ones via a retro-ene reaction with some nucleophiles gave regioselectively only 5-halo-4-substitutedpyridazin-6-ones.
Retro-Ene reaction.<b>VI.</b>Functionalization of 4,5-dihalopyridazin-6-ones using 1-acetyloxymethyl-4,5-dihalopyridazin-6-ones as the 1-O, 3-N, 5-O ene-adduct
Functionalization of 1-acetyloxymethyl-4,5-dihalopyridazin-6-ones via retro-ene reaction with some nucleophiles gave regioselectively only 5-halo-4-substitutedpyridazin-6-ones.