GENERAL STEPS: Methylmagnesium bromide (10.1 mL, 10.1 mmol, 1 M solution in ether) was added slowly and dropwise to a solution of N-methoxy-N-methylpyridazine-4-carboxamide (1.13 g, 6.76 mmol) in tetrahydrofuran (22 mL) under nitrogen protection. The reaction mixture was stirred at room temperature for 1 hour. Upon completion of the reaction, the reaction solution was mixed with saturated aqueous sodium chloride solution and extracted with chloroform. The organic layers were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=1/2→0/1) to afford 1-(pyridazin-4-yl)ethanone in 42% yield. Product characterization: light yellow solid; LC/MS (condition 7): retention time 0.75 min; LC/MS (ESI+) m/z: 123 [M+H]+; 1H-NMR (CDCl3) δ: 2.70 (s, 3H), 7.86 (dd, J=0.8 and 5.4 Hz, 1H), 9.48 (d, J=5.4 Hz, 1H),. 9.61 (d, J=0.8 Hz, 1H).
