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

Temperature

-78 °C

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).

1. customthe temperature below −60° C
2. customthe temperature below −60° C
3. temperaturewarmed to RT
4. customThe layers were separated
5. washthe water washed with ethyl acetate (2×50 ml), before the combined organic layers
6. washwere washed with 2M sodium hydroxide solution (50 ml)
7. additionThe combined aqueous layers were treated with 2M hydrochloric acid solution to pH 7.2
8. filtrationthe resultant precipitate collected by filtration
9. customdried in vacuo at 40° C. overnight

ORD record

ord-dbad9d30f5a1473291886aedecf70fb4

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658635B2