N,4-dimethoxy-N-methyl-6-oxo-[3-(trifluoromethyl)phenyl]-1,6-dihydropyridazine-3-carboxamide → 6-Acetyl-5-methoxy-2-[3-(trifluoromethyl)phenyl]pyridazin-3(2H)-one

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Reaction Steps

MeMgBr (1 M solution in THF, 4 mL, 12 mmol) was added dropwise at −78° C. to a solution of N,4-dimethoxy-N-methyl-6-oxo-1-[3-(trifluoromethyl)phenyl]-1,6-dihydropyridazine-3-carboxamide (1.43 g, 4 mmol) in THF (15 mL). After stirring for 1 h, the reaction mixture was quenched with saturated NH4Cl aqueous solution and extracted with AcOEt. The extract was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography eluting with hexane/AcOEt (1/1) and recrystallized from hexane/AcOEt to give the title compound (566 mg, 45% yield) as a white solid: mp 136-138° C.; NMR (300 MHz, CDCl3): δ ppm 2.57 (3H, s), 3.93 (3H, s), 6.31 (1H, s), 7.63 (1H, t, J=7.9 Hz), 7.69 (1H, d, J=7.9 Hz), 7.84-7.88 (1H, m), 7.91 (1H, s). Anal. Calcd for C14H11F3N2O3: C, 53.85; H, 3.55; N, 8.97. Found: C, 53.96; H, 3.57; N, 8.96.

Provenance & Evidence