Triisopropyl borate → 3-(1-Methylpiperidin-4-yl)-1H-Indole-5-Boronic Acid

Participants

Reaction Conditions

Reaction Steps

To a slurry of potassium hydride (20% suspension in mineral oil, 0.72 g, 3.58 mmol) in 7 mL of anhydrous tetrahydrofuran at 0° C. was slowly added dropwise 5-bromo-3-(1-methylpiperidin-4-yl)-1H-indole (1.0 g, 3.41 mmol) in 7 mL of anhydrous tetrahydrofuran. After stirring at 0° C. for 30 minutes, the mixture was cooled to −78° C., and tert-butyl lithium (1.7M in pentane, 7.51 mmol, 4.42 mL) was added dropwise. After 15 minutes, a solution of triisopropyl borate (6.82 mmol, 2.0 eq, 1.57 mL) in 2 mL of anhydrous tetrahydrofuran was added dropwise. The stirred mixture was allowed to warm to room temperature, and was quenched with 5N aqueous hydrochloric acid. The aqueous phase was extracted with diethyl ether, and the ether extracts were separated, washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo to give a crude white solid which was treated with hexanes, sonicated for 30 minutes, filtered and dried to give 0.252 g (29%) of the title compound as an amorphous white material which was used without further purification.

Provenance & Evidence