Sodium Sulfite → (5-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridin-4-yl)((3S)-3-(dibenzylamino)cyclopentyl)methanone

Participants

Reaction Conditions

Reaction Steps

A round-bottomed flask was charged with (5-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridin-4-yl)((3S)-3-(dibenzylamino)cyclopentyl)methanol (3.51 g, 5.83 mmol) in DCM (104 mL) to give a yellow solution. The solution was cooled to about 0° C. Dess-Martin periodinane (7.41 g, 17.48 mmol) was added and the mixture was stirred at about 0° C. for about 2 h then at ambient temperature for about 3 h. The reaction mixture was then re-cooled to about 0° C. and saturated aqueous sodium sulfite (50 mL) was added slowly. The organic solvent was removed under reduced pressure. EtOAc (100 mL) was added and the layers were partitioned. The organic layer was washed with saturated aqueous NaHCO3 (2×20 mL) and brine (3×50 mL), dried over anhydrous MgSO4, filtered, and the solvent was removed under reduced pressure to give a brown oil. The crude material was purified by silica gel chromatography eluting with 5% EtOAc in heptane. A second purification by neutral alumina chromatography eluting with a step-wise gradient of 0-100% EtOAc in heptane yielded (5-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridin-4-yl)((3S)-3-(dibenzylamino)cyclopentyl)methanone (1.7 g, 50%) as a yellow oil: LC/MS (Table 2, Method n) Rt=3.90 min; MS m/z: 601 (M+H)+.

Provenance & Evidence