To a solution of (S)-4-(3-(4-bromophenyl)-3-o-tolylpropanoyl)pyridazin-3(2H)-one (293 mg, 679 μmol) in N,N-dimethylacetamide (4 mL) was added iodomethane (101 mg, 712 μmol) followed by potassium carbonate (103 mg, 746 μmol). The reaction mixture was stirred for 5½ h at room temperature and then partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, filtered, and evaporated. Chromatography (SiO2, gradient heptane to heptane/ethyl acetate 1:1) produced the title compound (251 mg, 90%). White solid, MS: 411.2 [M+H]+.
