1-(4-Bromo-2,5-difluorophenyl)-N,5-dimethoxy-N-methyl-4-oxo-1,4-dihydropyridazine-3-carboxamide → 3-Acetyl-1-(4-bromo-2,5-difluorophenyl)-5-methoxypyridazin-4(1H)-one

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(4-bromo-2,5-difluorophenyl)-N,5-dimethoxy-N-methyl-4-oxo-1,4-dihydropyridazine-3-carboxamide (5.0 g, 12 mmol) in THF (100 mL) was added dropwise to MeMgBr (1.0 M in THF, 50 mL, 50 mmol) at −78° C. under N2. The mixture was stirred at −78° C. for 1 h. The reaction was quenched with 1 M HCl aqueous solution (70 mL) at −78° C. The mixture warmed up to room temperature and extracted with AcOEt. The organic layer was dried over MgSO4 and concentrated under reduced pressure to give the title compound (3.6 g, 80% yield) as a yellow solid: 1H NMR (300 MHz, DMSO-d6): δ ppm 2.50 (3H, s), 3.80 (3H, s), 8.03 (1H, dd, J=8.9, 6.6 Hz), 8.17 (1H, dd, J=10.0, 6.2 Hz), 8.52 (1H, d, J=1.5 Hz). LC-MS (ESI) m/z 360 [M+H]+.

Provenance & Evidence