Hydrochloric Acid → HCID 11595204, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-fluoro-1-(triisopropylsilyl)-1H-indole (2.5 g, 8.58 mmol), 2,2,6,6-tetramethylpiperidine (2.42 g, 17.15 mmol), potassium 2-methylpropan-2-olate (1.92 g, 17.15 mmol) in anhydrous THF (75 mL) under nitrogen at −78° C. was added dropwise a solution of n-BuLi in THF (1.6 M, 10.7 mL, 17.15 mmol) at a rate to maintain the internal reaction temperature below −70° C. The mixture was then stirred at −78° C. for 2 h. The reaction mixture was poured into a slurry of ice (100 g), water (200 mL), and DCM (100 mL). The pH of aqueous phase was adjusted to 4.0 with HCl (2 M). A precipitate was formed, which was filtered, washed with water (10 mL) and ethoxyethane (10 mL) to afford 5-fluoro-1-(triisopropylsilyl)-1H-indole-4-carboxylic acid as a white solid (580 mg, 20.2%). MS (ESI): m/z=336.2 [M+1]+.

Provenance & Evidence