Triisopropyl borate → (2-[(tert-Butoxycarbonyl)amino]pyridin-3-yl)boronic acid

Temperature

-6 °C

Under a nitrogen atmosphere, a solution of tert-butyl N-(2-pyridyl)carbamate (15.71 g, 80.9 mmol) and N,N,N′N′-tetramethylethylenediamine (TMEDA, 25.3 g, 218 mmol) in THF (400 mL) was cooled to −78° C. n-Butyllithium (81 mL of a 2.5 M solution in hexanes) was added dropwise over a period of 20 minutes. The solution was stirred for ten minutes, and then the addition funnel was rinsed with additional THF (20 mL). The solution was warmed to −6° C., stirred for two hours, and cooled again to −78° C. Triisopropyl borate (57.7 g, 307 mmol) was added over a period of ten minutes. The resulting solution was warmed to 0° C. and then poured into saturated aqueous ammonium chloride (500 mL). A yellow solid formed and was stirred with diethyl ether (300 mL), isolated by filtration, washed with diethyl ether and water, and air-dried overnight to provide 2-tert-butoxycarbonylamino-3-pyridylboronic acid as a yellow solid.

1. additionwas added dropwise over a period of 20 minutes
2. washthe addition funnel was rinsed with additional THF (20 mL)
3. stirringstirred for two hours
4. temperaturecooled again to −78° C
5. temperatureThe resulting solution was warmed to 0° C.
6. customA yellow solid formed
7. customisolated by filtration
8. washwashed with diethyl ether and water
9. customair-dried overnight

ORD record

ord-aedff21ccdfb4e7fb78550bdd41cddf9

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07879849B2