CN(C)[CH:3]=[CH:4][C:5]([C:7]1[CH:12]=[CH:11][C:10]([O:13][CH3:14])=[CH:9][C:8]=1[OH:15])=[O:6].[I:17]N1C(=O)CCC1=O.CO>C(Cl)(Cl)Cl>[I:17][C:4]1[C:5](=[O:6])[C:7]2[C:8](=[CH:9][C:10]([O:13][CH3:14])=[CH:11][CH:12]=2)[O:15][CH:3]=1To a solution of 3-(dimethylamino)-1-(2-hydroxy-4-methoxyphenyl)prop-2-en-1-one (20.0 g, 90.37 mmol) in anhydrous chloroform (100 ml) at 0° C. was added N-iodosuccinimide (23.5 g, 99.22 mmol) and silica gel (40 g). The reaction mixture was stirred at 0° C. for 60 minutes, then the insoluble material filtered off. The filtrate was washed with aqueous sodium thiosulfate (0.5M, 2×50 ml), followed by brine (100 ml), then dried over sodium sulfate. The solvent was removed under reduced pressure, providing an orange solid. To this solid was added methanol (30 ml), and the mixture was sonicated, filtered, the solid washed with methanol (2×5 ml), and the solid dried under reduced pressure, to give 3-iodo-7-methoxychromen-4-one as a pale yellow solid.
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