[Na+].[N:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[S:8]([O-:10])=[O:9].Br[C:12]1[CH:16]=[CH:15][S:14][C:13]=1[CH:17]=[O:18]>CS(C)=O>[N:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[S:8]([C:12]1[CH:16]=[CH:15][S:14][C:13]=1[CH:17]=[O:18])(=[O:10])=[O:9]A mixture of pyridine-2-sulfinate sodium salt (8.5 g), 3-bromothiophene-2-carbaldehyde (6.5 g) and dimethyl sulfoxide (50 mL) (split equally into four microwave vials) was heated by microwave irradiation at 125° C. for 45 minutes. The combined mixtures were diluted with ethyl acetate, washed with saturated aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride solution and dried over magnesium sulfate. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel, eluting with a mixture of dichloromethane and ethyl acetate (1:0 to 0:1 by volume) to afford the title compound as a yellow solid (0.55 g).
Wird geladen…