4-Hydroxybiphenyl → HCID 10296468, compound

Participants

Reaction Steps

A solution of triphenylphosphine (0.24 g, 0.915 mmol) in 5 mL of dry THF was treated at 0° C. with diethylazodicarboxylate (0.159 g, 0.915 mmol) and stirred for 20 min. A solution of (2S)-3-[4-(5-hydroxy-pent-1-ynyl)-phenyl]-2-methoxy-propionic acid ethyl ester (Example 21, Step A) (0.18 g, 0.61 mmol) and 4-phenylphenol (0.156 g, 0.915 mmol) in 2 mL of dry THF was added, and the mixture was stirred at room temperature overnight. The mixture was concentrated under vacuum and purified by silica gel chromatography (silica gel, hexanes/ethyl acetate 10:1 to 3:1). Fractions with Rfs 0.48 and 0.45 (hexanes/ethyl acetate 2:1) corresponding to the coupled compound and starting phenol, respectively, were combined and concentrated. The mixture was dissolved in 5 mL of methanol and was treated with a mixture of 75 mg of mercury (II) oxide and 4% sulfuric acid in water. The solution was stirred at 55° C. for 3 h, cooled to room temperature, diluted with saturated aqueous NaHCO3 (20 mL), and extracted with dichloromethane (4×20 mL). The combined organic layers were washed with brine (20 mL), dried (MgSO4), and concentrated. The residue was dissolved in 6 mL of methanol and 2 mL of 1N NaOH and stirred for 2 hours. The methanol was evaporated under vacuum, and the aqueous solution was diluted with brine (6 mL) and washed with diethyl ether (3×15 mL). The aqueous layer was acidified with 1N HCl (pH 1–2) and extracted with ethyl acetate (3×15 mL). The combined extracts were dried (MgSO4) and concentrated to a white solid (19%). 1H-NMR (200.15 MHz, CDCl3): δ 7.89 (d, 2H, J=8.4), 7.55–7.23 (m, 9H), 6.93 (d, 2H, J=8.8), 4.06–3.99 (m, 3H), 3.38 (s, 3H), 3.18 (dd, 1H, J=4.3, 4.4), 3.03 (t+m, 3 H, J=6.9), 1.96–1.86 (m, 4H).

Provenance & Evidence