Boron tribromide → (2S)-2-(3-{5-[(4R,5S)-4,5-Dimethyl-4,5-dihydro-1,3-oxazol-2-yl]-1H-pyrrol-2-yl}-5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}phenoxy)propan-1-ol

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Reaction Conditions

Reaction Steps

5-(3-{5-[(4R,5S)-4,5-Dimethyl-4,5-dihydro-1,3-oxazol-2-yl]-1H-pyrrol-2-yl}-5-[(1S)-2-methoxy-1-methylethoxy]phenoxy)-2-(methylsulfonyl)pyridine (0.95 g, 1.96 mmol) synthesized in Example (88c) was dissolved in methylene chloride (20 mL) and cooled to −78° C., and boron tribromide (1.0 mol/L methylene chloride solution, 2.15 mL, 2.15 mmol) was added under nitrogen atmosphere. After the temperature was raised naturally and the solution was stirred at room temperature for 30 minutes, a saturated aqueous sodium hydrogencarbonate solution was added to neutralize the reaction solution, followed by extraction with methylene chloride (80 mL). The organic layer was washed with saturated brine, and subsequently dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting residue was purified using silica gel column chromatography (elution solvent: ethyl acetate/hexane=70%-100%) to afford the desired compound (617 mg, 67%) as a white solid.

Provenance & Evidence