Potassium Carbonate → 3-Chloro-6-(1-methyl-1H-pyrazol-4-yl)pyridazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 3,6-dichloropyridazine (20.1 g, 135 mmol), 1-methyl-4-pyrazoleboronic acid pinacol ester (22.46 g, 108 mmol) and K2CO3 (44.71 g, 324 mmol) in 500 mL of dioxane and 200 mL of H2O was degassed with nitrogen. To this mixture was added dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II) dichloromethane adduct (5.28 g, 7.2 mmol) and the resulting mixture was bubbled with nitrogen for another 20 min. The reaction mixture was heated at 80° C. for 4 h, then concentrated in vacuo. The residue was purified by flash column chromatography with dichloromethane as eluent to provide 21 g of 3-chloro-6-(1-methyl-1H-pyrazol-4-yl)-pyridazine (76% yield): 1H NMR (CDCl3) δ 3.99 (s, 3H), 7.45 (d, 1H), 7.56 (d, 1H), 7.97 (s, 1H), 8.11 (s, 1H).

Provenance & Evidence