Triisopropyl borate → (2-Methyl-1H-pyrrolo[2,3-b]pyridin-4-yl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of 60% sodium hydride in mineral oil (1.18 g) in THF (25 ml) at 0° C. was added 4-bromo-2-methyl-1H-pyrrolo[2,3-b]pyridine (5 g) in THF (75 ml) dropwise. The reaction was cooled to −78° C. and 1.6M n-butyl lithium in hexane (30 ml) was added dropwise, keeping the temperature below −60° C. The reaction was stirred at −78° C. for 30 min before the dropwise addition of triisopropylborate (16.4 ml), keeping the temperature below −60° C. The reaction was stirred for 1 h at −78° C., warmed to RT and water (100 ml) was added. The layers were separated and the water washed with ethyl acetate (2×50 ml), before the combined organic layers were washed with 2M sodium hydroxide solution (50 ml). The combined aqueous layers were treated with 2M hydrochloric acid solution to pH 7.2 and the resultant precipitate collected by filtration and dried in vacuo at 40° C. overnight to give title compound (2.64 g).

Provenance & Evidence