Water → 3-ethenyl-6,7-dihydro-5H-pyrano[2,3-c]pyridazine

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Reaction Steps

Argon was bubbled for 15 minutes through a solution of 6,7-dihydro-5H-pyrano[2,3-c]pyridazin-3-yl trifluoromethanesulfonate (228 mg, 0.8 mmol) in 1,2-dimethoxyethane (6.5 ml). Tetrakis(triphenylphosphine)palladium(0) (50 mg, 0.0475 mmol) was added and the solution stirred for 20 minutes under argon. The mixture was then treated with potassium carbonate (111 mg, 0.8 mmol), water (1.9 ml) and triethenylboroxin pyridine complex (180 mg, 0.75 mmol). After stirring for 2 hours at 80° C., the mixture was cooled and partitioned between DCM and saturated aqueous sodium bicarbonate solution. Layers were separated and the aqueous was extracted twice with 20% MeOH/DCM. The combined organic solution was dried over magnesium sulfate, evaporated and the residue chromatographed on silica, eluting with ethyl acetate to give the product as a white solid (100 mg, 77%).

Provenance & Evidence