Ethyl chloroformate → HCID 58382073, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (0.856 g, 2.77 mmol, Preparation #1, Step A) in THF (20 mL) at about −78° C. was added sec-BuLi (4.35 mL1, 6.10 mmol) dropwise. The reaction was stirred at −78° C. for about 80 min. To the mixture was added ethyl chloroformate (0.665 mL, 6.93 mmol. The flask was removed from the cooling bath and stirred for about 70 min at rt. The mixture was quenched by the addition of a saturated aqueous NH4Cl (5 mL). EtOAc (20 mL) and water (20 mL) were added and the layers were separated. The aqueous layer was extracted with EtOAc (2×15 mL), and the combined organic layers were washed with brine (20 mL). The organic layer was dried over MgSO4, filtered, and concentrated in vacuo. The material was purified by flash chromatography (40 g Redi-Sep™ silica column) eluting with 0-10% EtOAc in heptane to give ethyl 4-chloro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine-5-carboxylate (1.02 g, 97%): 1H NMR (400 MHz, DMSO) δ 8.69 (s, 1H), 7.69 (d, J=3.6, 1H), 6.72 (dd, J=68.4, 3.5, 1H), 4.34 (q, J=7.0, 2H), 1.86 (dt, J=15.0, 7.5, 3H), 1.34 (t, J=7.1, 3H), 1.05 (d, J=7.5, 18H).

Provenance & Evidence