Cesium carbonate → 4-[2-(Benzyloxy)-5-(trifluoromethyl)phenyl]pyridazine

Participants

Reaction Steps

([2-(benzyloxy)-5-(trifluoromethyl)phenyl]boronic acid (3.72 g, 0.0126 mol) and caesium carbonate (8.9 g, 0.0273 mol) were suspended in 1,4 dioxane (40.0 mL) and water (20.0 mL). The reaction was degassed twice before being brought to 80° C. under nitrogen. Then 4-bromopyridazine hydrobromide (Preparation see above, 2.52 g, 0.0105 mol) and palladium tetrakistriphenylphosphine (0.62 g, 0.000537 mol) were added to the reaction and it was stirred for three hours. The reaction was concentrated in vacuo to 20.0 mL, and partitioned between ethyl acetate (70.0 mL) and saturated aqueous brine (50.0 mL). The two layers were filtered over Arbocel™ to remove a fine black solid. Then the organic layer was washed with more saturated aqueous brine (2×50.0 mL) and it was dried over sodium sulphate. The solvents were concentrated in vacuo and crude was purified using ISCO™ (using a gradient of 0-50% ethyl acetate in heptane, 80 g SiO2) to afford the title compound as a light orange solid.

Provenance & Evidence