Hydrochloric Acid → HCID 67247636, compound

Participants

Reaction Conditions

Reaction Steps

Triethylamine (13 μL, 0.09 mmol, 1.2 eq) is added at room temperature to a stirred solution of 6-methoxy-2H-1-oxa-9-aza-phenanthrene-3-carboxylic acid (20 mg, 0.08 mmol, 1.0 eq) in dichloromethane (1 mL), followed by a solution of diphenylphosphoryl azide (23 mg, 0.08 mmol, 1.0 eq) in toluene (1.5 mL). After 1 h 30 stirring at 80° C., 6M hydrochloric acid aqueous solution (0.5 mL) is added and the resulting mixture is heated at 90° C. for 2 hours. The reaction mixture is then cooled down to room temperature and extracted with ethyl acetate (3×10 mL) and saturated sodium hydrogen carbonate aqueous solution (10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a residue that is purified by column chromatography (silica gel, eluent: ethyl acetate) to afford 6-methoxy-4H-1-oxa-9-aza-phenanthrene-3-one as a yellow semisolid (5 mg, 28% yield).

Provenance & Evidence