(Dimethyl sulfide)trihydroboron → (1R)-1-[6-(2,5-dimethyl-1H-pyrrol-1-yl)-3-pyridinyl]-2-({[(2R)-6-iodo-3,4-dihydro-2H-chromen-2-yl]methyl}amino)ethanol

Participants

Reaction Steps

To a solution of (2R)-N-{(2R)-2-[6-(2,5-dimethyl-1H-pyrrol-1-yl)-3-pyridinyl]-2-hydroxyethyl}-6-iodo-3,4-dihydro-2H-chromene-2-carboxamide (Example 355, 7.67 mmol, 1 eq.) in THF (150 mL) at room temperature was added slowly borane-methyl sulfide complex (2M in THF, 38.4 mmol, 5.0 eq.). After completion of the addition, the reaction mixture was heated to reflux for 2 hours and was then cooled to room temperature. The excess borane was quenched by the dropwise addition of EtOH (9 mL) followed by the slow addition of 2 M HCl (40 mL). The resulting mixture was heated to reflux for 1 hour and was then allow to cool to room temperature. The mixture was basified with 1N NaOH and extracted with ethyl acetate. The organic extract was washed with brine, dried over anhydrous sodium sulfate, concentrated, and purified by medium pressure column chromatography (Biotage 40S normal phase silica gel column, using a gradient of 1:4 hexanes:EtOAc to 1:10 MeOH:EtOAc). The product was obtained as a pale yellow oil in 63% yield. MH+=503.9, RT=3.23 min.

Provenance & Evidence