Ethanol → 6-(Ethoxycarbonyl)chromane-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A 2-neck round bottom flask fit with a reflux condenser was charged the compound from Example 28 (1.05 g, 3.45 mmol) and palladium (II) acetate (23 mg, 0.10 mmol). The flask was placed under an atmosphere of carbon monoxide (1 atm). Triethylamine (1.20 mL, 8.63 mmol) and absolute ethanol (2.0 mL) were added via syringe. The dark reaction mixture was heated to 60° C. and stirred for 60 h. The reaction mixture was cooled to room temperature and diluted with ethyl acetate (100 mL). The resulting dark solution was washed sequentially with 7% aqueous hydrochloric acid, water, and saturated aquesous sodium chloride. The organic layer was dried (MgSO4), and concentrated to an orange oil which crystallized on standing to a pale solid (0.675 g, 81%). 1H NMR (300 MHz, DMSO-d6) δ 13.03 (s, 1H), 7.68 (m, 2H), 6.90 (m, 1H), 4.89 (m, 1H), 4.25 (q, J=7.36 Hz, 2H), 2.82 (m, 1H), 2.66 (m, 1H), 1.28 (t, J=6.98 Hz, 3H); MS (CI) m/z 251 (MH+).

Provenance & Evidence