反应详情

A solution of (E)-7-benzylidene-3-bromo-6,7-dihydro-5H-cyclopenta[b]pyridine (1.61 g, 5.63 mmol) in MeOH (75 mL) and DCM (75 mL) was cooled to −78° C. and a stream of ozone in oxygen was bubbled through the solution for 10 min until the solution turned light blue. Oxygen was pass through the solution for 10 min until the solution turned colorless. Triphenylphosphine (3.63 g, 13.8 mmol) was added and the reaction mixture was allowed to warm to room temperature. The reaction mixture was stirred at room temperature for 1.5 h and then concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel (80 g, 30% to 70% EtOAc in heptane) to give 3-bromo-5H-cyclopenta[b]pyridin-7(6H)-one (1.14 g, 5.38 mmol, 96% yield) as a yellow solid. MS m/z=211.9 [M+H]+. Calculated for C8H6BrNO 211.0.

1. customa stream of ozone in oxygen was bubbled through the solution for 10 min until the solution
2. customfor 10 min
3. concentrationconcentrated under reduced pressure
4. customThe residue was purified by flash column chromatography on silica gel (80 g, 30% to 70% EtOAc in heptane)