Sulfuric Acid → 6-nitro-3,4-dihydro-2H-1-benzopyran-4-one

Participants

Reaction Conditions

Reaction Steps

Mix 3-(4-nitrophenoxy)propanoic acid (6.5 g, 30 mmol) and concentrated H2SO4 (30 mL). Once dissolved, add P2O5, stir at 65° C. for 3 hrs. Cool to room temperature, pour slowly the reaction mixture to ice water (50 mL), stir for 15 min, and extract with EtOAc (100 mL×3). Combine the organic layers, wash with brine (100 mL×2), dry over anhydrous Na2SO4, concentrate to give the crude product. Purification by chromatography (silica gel, EtOAc:PE=1:1) affords the title compound (4.6 g, 77.8%). MS: (M−1): 192.2.

Provenance & Evidence