Phosphorus oxychloride → 8-bromo-2-chloro-4-nitro-10H-chromeno[3,2-b]pyridin-10-one

Participants

Reaction Conditions

Reaction Steps

A suspension of 8-bromo-4-nitro-10-oxo-10H-chromeno[3,2-b]pyridine 1-oxide (90 mg, 0.267 mmol) in 1 mL of dry DMF was added dropwise to a solution of phosphorus oxychloride (44.0 μL, 0.481 mmol) in 0.2 mL of DMF and 0.5 mL of toluene at 0° C. After stirring at 0° C. for 0.5 h, the reaction was quenched with saturated NaHCO3 and extracted with ethyl acetate (5×5 mL). The combined organics were dried over sodium sulfate, filtered and evaporated to dryness. Purification of the crude residue by column chromatography (CH2Cl2 to CH2Cl2/EA=100:3) gave 8-bromo-2-chloro-4-nitro-10H-chromeno[3,2-b]pyridin-10-one as a light yellow solid.

Provenance & Evidence