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

Participants

Reaction Conditions

Reaction Steps

{(4R)-2-[5-(3-[(1S)-2-Methoxy-1-methylethoxy]-5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}phenyl)-1H-pyrrol-2-yl]-4,5-dihydro-1,3-oxazol-4-yl}methanol (200 mg, 0.40 mmol) synthesized in Example (86c) was dissolved in methylene chloride (5 mL), followed by cooling to −78° C., and boron tribromide (1.0 mol/L methylene chloride solution, 0.80 mL, 0.80 mmol) was added under nitrogen atmosphere. After the temperature was raised naturally and stirring was carried out 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 1N aqueous sodium hydroxide solution and 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: methanol/methylene chloride=0%-4%) to afford the desired compound (143 mg, 74%) as a white solid.

Provenance & Evidence