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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence