5-Chloro-4-iodo-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine → (5-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridin-4-yl)((3R)-3-(dibenzylamino)cyclopentyl)methanol

Participants

Reaction Steps

A solution of 5-chloro-4-iodo-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (1.23 g, 2.83 mmol, Adesis) in THF (10 mL) was cooled to about −78° C. and n-BuLi (1.6 M in hexanes, 2.3 mL, 3.7 mmol) was added drop-wise while keeping the temperature below about −70° C. The mixture was stirred for about 40 min, and a solution of (3R)-3-(dibenzylamino)cyclopentanecarbaldehyde (0.83 g, 2.8 mmol, Step B) in THF (3 mL) was added drop-wise, and the resulting mixture was stirred at about −75° C. for about 2 h. The reaction mixture was quenched by a drop-wise addition of saturated aqueous NH4Cl (20 mL), and the organic solvent was removed under reduced pressure. The aqueous mixture was extracted with EtOAc (25 mL) and the organic layer was washed with brine (20 mL) and concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with a gradient of 0-20% EtOAc in heptane to yield (5-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridin-4-yl)((3R)-3-(dibenzylamino)cyclopentyl)methanol (1.14 g, 67%): LC/MS (Table 2, Method a) Rt=3.31 min; MS m/z: 602 (M+H)+.

Provenance & Evidence