N-(2,4-difluorophenyl)-2,2-dimethylpropanamide

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of N-(2,4-difluorophenyl)pivalamide (740 mg, 3.46 mmol, 1.2 eq.) in THF (10 mL) cooled at −78° C. was added n-BuLi (2.76 mL, 6.9 mmol, 2.4 eq.) dropwise. The resulting mixture was stirred at −78° C. for 1 h, then a solution of quinoxaline-6-carbaldehyde (450 mg, 2.88 mmol, 1.0 eq.) in THF (20 mL) was added dropwise. The mixture was stirred at −78° C. for 1 h, then quenched by the addition of NH4Cl solution. The mixture was extracted with EA (20 mL×3) and the combined organic layers were dried over Na2SO4 and concentrated. The resulting residue was purified via flash column chromatography (PE/EA=2/1, v/v) to afford N-(2,4-difluoro-3-(hydroxy(quinoxalin-6-yl)methyl)phenyl)pivalamide as a yellow foam (541 mg, 50.7%). The mixture was stirred at −78° C. for 1 h quenched by the addition of NH4Cl solution The mixture was extracted with EA (20 mL×3) the combined organic layers were dried over Na2SO4 concentrated The resulting residue was purified via flash column chromatography (PE/EA=2/1