Ammonium Chloride → 3-acetyl-5-methoxy-1-phenylpyridazin-4(1H)-one

Participants

Reaction Conditions

Reaction Steps

Under an argon atmosphere, to a stirring solution of N,5-dimethoxy-N-methyl-4-oxo-1-phenyl-1,4-dihydropyridazine-3-carboxamide (20 g) in tetrahydrofuran (1 L) was added dropwise, under cooling at −69° C., methyl magnesium bromide solution (1 M in THF, 138 mL). After stirring at −69° C. for 1.5 hr, a saturated aqueous ammonium chloride solution was added. Thereafter, the mixture was warmed to room temperature in 1.5 hr, and the reaction mixture was partitioned. The organic layer was washed with saturated brine, and dried over anhydrous magnesium sulfate. The aqueous layer was extracted with ethyl acetate, and the obtained extract was dried over anhydrous magnesium sulfate. The organic layer and the extract were combined, and concentrated under reduced pressure to dryness. The residue was purified by silica gel column chromatography (ethyl acetate/methanol) to give the title compound (13.22 g) as a pale-yellow solid.

Provenance & Evidence