Triisopropyl borate → 6-(Boc-methylamino)pyridine-3-boronic acid pinacol ester

Participants

Reaction Conditions

Reaction Steps

To a solution of (5-bromo-pyridin-2-yl)-methyl-carbamic acid tert-butyl ester (3.286 g) in THF (50 mL) at −78° C. was added n-butyllithium (5.15 mL of a 2.5 M solution in hexanes). After stirring at −78° C. for 20 min, triisopropyl borate (5.31 mL) was added. The reaction was warmed to −45° C. over 4 h, then, neopentyl glycol (1.19 g) was added. The reaction was warmed to room temperature over 16 h and then quenched with ice/water (70 mL) and extracted into dichloromethane (3×40 mL). The organic layers were dried (MgSO4), reduced in vacuo and purified on silica to give methyl-[5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-pyridin-2-yl]-carbamic acid tert-butyl ester as an off-white solid.

Provenance & Evidence