Phosphorus oxybromide → HCID 57506731, compound

Participants

Reaction Conditions

Reaction Steps

A 250 mL round-bottomed flask, under nitrogen, fitted with a thermometer probe and a condenser/inert gas bubbler (via a Claisen head), was charged with a solution of 1-benzenesulfonyl-1H-pyrrolo[3,2-c]pyridine 5-oxide (3.5 g, 12.8 mmol) in acetonitrile (50 mL) and dioxane (50 mL). To this solution was added dropwise phosphorus oxybromide (12 g, 40.9 mmol) and the resulting mixture was stirred at 70° C. for 18 h. The precipitate formed was removed by filtration and washed several times with dioxane. The solution was concentrated in vacuo and partitioned between DCM, water and brine. The organic layer was isolated then dried (Na2SO4) and concentrated in vacuo. The resultant residue was purified by flash chromatography (Si—PCC, 0-20% EtOAc in cyclohexane) to give the desired product (3.1 g, 72%). 1H NMR (CDCl3, 300 MHz): δ 8.23 (d, J=5.7 Hz, 1 H); 7.94-7.85 (m, 3 H); 7.67-7.59 (m, 2 H); 7.55-7.48 (m, 2 H); 6.75 (dd, J=3.7, 0.8 Hz, 1 H).

Provenance & Evidence