N-Methoxy-N-methylacetamide → 1460286-48-9

A solution of 4-bromo-1-tert-butyl-1H-pyrazole (973 mg, 4.79 mmol) in anhydrous THF (9.5 ml) was cooled to −78° C. under argon. A solution of n-BuLi in Hexanes (1.6 M, 3.2 mL, 5.12 mmol) was then added dropwise over 5 min and reaction mixture was stirred at −78° C. for 80 min. A solution of N-methoxy-N-methylacetamide (0.55 ml, 5.17 mmol) in THF (3 mL) was added dropwise and mixture was warmed to 0° C. After 4 hours, reaction mixture was quenched via addition of NH4Cl (aq) (10 mL) and mixture was extracted with ethyl acetate. Combined organic layers were washed with 50% brine, dried (Na2SO4), filtered, and concentrated under reduced pressure. Resulting residue was purified by silica gel column chromatography (0-50% ethyl acetate in hexanes) to yield 1-(1-tert-butyl-1H-pyrazol-4-yl)ethanone 5.14.