Water → 1-(5-Bromo-3-(tert-butylamino)quinoxalin-2-yl)ethanol

Participants

Reaction Conditions

Reaction Steps

Methylmagnesium bromide (Aldrich) (3.0M in Et2O; 2.23 mL, 6.70 mmol) was added to a solution of 5-bromo-3-(tert-butylamino)quinoxaline-2-carbaldehyde (306a) (983.0 mg, 3.19 mmol) in THF (15.0 mL) at 0° C., and the resulting solution was stirred at 0° C. for 5 min. Water (5 mL) was added, and the resulting mixture was partitioned between saturated aq. NaHCO3 (80 mL) and EtOAc (120 mL). The organic layer was separated and sequentially washed with brine (60 mL), dried over Na2SO4, filtered, and concentrated in vacuo. Chromatographic purification of the residue (silica gel, 0-40% EtOAc/hexanes) furnished 1-(5-bromo-3-(tert-butylamino)quinoxalin-2-yl)ethanol (952 mg, 2.94 mmol, 92% yield) as a light-yellow solid (following trituration with hexanes). 1H NMR (400 MHz, CDCl3) δ ppm 7.83 (1H, dd, J=7.6, 1.4 Hz), 7.75 (1H, dd, J=8.2, 1.4 Hz), 7.19 (1H, t, J=7.9 Hz), 5.74 (1H, br. s.), 5.01 (1H, q, J=6.7 Hz), 3.55 (1H, br. s.), 1.63 (9H, s), 1.59 (3H, d, J=6.7 Hz). m/z (EST, +ve) 324.1/326.1 (M+H)+.

Provenance & Evidence