Cfc 113 → 4-chloro-5-fluoro-1H-indole-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

2,2,6,6-Tetramethylpiperidine (1.06 g, 7.5 mmol), N,N′,N″,N″-pentamethyldiethylene triamine (3.46 g, 20 mmol) and compound 1 (1.45 g, 5.0 mmol) were added consecutively to a solution of n-BuLi (2.5 M in hexanes, 8 mL, 20 mmol) in THF (20 mL) and hexanes (6 mL) at −78° C. After stirring for 4 h at −78° C., the mixture was treated with 1,1,2-trichloro-1,2,2-trifluoroethane (1.18 g, 6.0 mmol) before it was warmed to 25° C. Water was added to the mixture. The organic phase was washed with brine, dried with sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by SiO2 column chromatography (PE) to provide title compound (1.2 g, 73.8%) as a colorless liquid.

Provenance & Evidence