Carbon Dioxide → 3,5,3'-Trihydroxy-biphenyl-4-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To 308 mg (1.52 mmol) of 3,5,3′-trihydroxybiphenyl was added 400 mg (4.0 mmol) of KHCO3, then 1 ml of glycerol. The reaction was stirred at 130° C. under 1 atm of CO2 for 1 hour. Following this period of heating, the thick mixture was transferred to a sealed tube, the space above the mixture was purged with CO2, then the reaction was heated at 120° C. for 15 hour, and at ambient temperature for 96 hours. The reaction was diluted with 10 mL of water, 5 mL of 1M HCl was added slowly, then the mixture was extracted with ethyl acetate (3×5 mL). The combined organic layers were back extracted with water (1×5 mL), and brine (1×5 mL), dried over MgSO4, filtered, and concentrated to a dark residue. This was taken up in ethyl acetate and methanol, and treated with ethereal diazomethane until the acid was no longer visible by TLC and a new, higher Rf spot appeared (40% ethyl acetate:hexanes). The product was purified by silica gel chromatography, eluting with 40% ethyl acetate:hexanes to give 100 mg (26%) of 3,5,3′-trihydroxy-biphenyl-4-carboxylic acid methyl ester as a white solid. 1H NMR (300 MHz, d6-DMSO) δ 10.15 (bs, 2H), 9.56 (bs, 1H), 7.25 (t, 1H, J=7.8 Hz), 6.97 (dd, 1H, J=1.0, 9.2 Hz), 6.92 (t, 1H, J=2.0 Hz), 6.87 (dd, 1H, J=2.4, 8.0 Hz), 6.57 (s, 2H), 3.33 (s, 3H); MS (ESI) m/z=259 (M−H).

Provenance & Evidence