Dimethyl Sulfate → 5,6-bis(4-methoxyphenyl)-2-[4-(dimethylamino)benzyl]-2H-pyridazin-3-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(4-aminobenzyl)-5,6-bis(4-methoxyphenyl)-2H-pyridazin-3-one (245 mg, 0.6 mmol) in acetone/N,N-dimethylformamide (5/1) (6 ml), sodium hydrogencarbonate (378 mg, 4.5 mmol) and a solution of dimethyl sulfate in acetone [an acetone solution of dimethyl sulfate (631 mg) (total volume: 5 ml); 3.0 ml, 3.0 mmol)] was added, followed by stirring under heat at 60° C. for 90 minutes. After the acetone was distilled off, the residue was extracted with ethyl acetate. The organic layer was washed successively with water and a brine, and was then dried over anhydrous sodium sulfate. The solvent was distilled off. The pale orange oil (238 mg) was separated and purified by silica gel preparative chromatography [developer: chloroform/methanol (20/1)], whereby 5,6-bis(4-methoxyphenyl)-2-[4-(dimethylamino)benzyl]-2H-pyridazin-3-one (80.6 mg, 30.8%) was obtained as a reddish brown oil from fractions having large Rf values. 1H-NMR (CDCl3) δ: 2.94(6H,s), 3.79(6H,s), 5.32(2H,s), 6.71(2H,d,J=8.79 Hz), 6.78(2H,d,J=8.79 Hz), 6.79(2H,d,J=9.03 Hz), 6.85(1H,s), 7.07(2H,d,J=8.79 Hz), 7.11(2H,d,J=9.03 Hz), 7.48(2H,d,J=8.79 Hz).

Provenance & Evidence