Diisopropylamine → 1-(1-benzenesulfonyl-1H-pyrrolo[2,3-b]pyridin-2-yl)-3,3-dimethyl-butan-1-ol

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Reaction Conditions

Reaction Steps

To a suspension of 1-benzenesulfonyl-1H-pyrrolo[2,3-b]pyridine (3.5 g, 13 mmol) in dry tetrahydrofuran (150 mL) at −78° C. was added freshly prepared lithium diisopropylamide [prepared by adding 1.6 M n-butyllithium in n-hexane (12.5 mL, 20 mmol) to a 0° C. solution of diisopropylamine (3.06 mL, 21 mmol) in dry tetrahydrofuran (10 mL)] dropwise. The mixture was stirred at −78° C. for 15 min and then treated with 3,3-dimethyl-butyraldehyde (3.1 mL, 24 mmol) dropwise. The resulting mixture was stirred at −78° C. for 1 h and quenched with brine. The mixture was extracted with ethyl acetate (2×150 mL), washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo. Purification by flash column chromatography (QingDao silica gel, 200-300 mesh, 25% ethyl acetate/hexanes) afforded 1-(1-benzenesulfonyl-1H-pyrrolo[2,3-b]pyridin-2-yl)-3,3-dimethyl-butan-1-ol as a colorless oil (3.1 g, 63%): LC/MS m/e calcd for C19H22N2O3S [M+H]+ 359.46, observed 359.2.

Provenance & Evidence