[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][C:13]([C:17](=[S:19])[NH2:18])=[CH:14][CH:15]=2)[CH:10]=[CH:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].Br[CH2:21][C:22](=O)[C:23]([O:25][CH2:26][CH3:27])=[O:24]>CCO>[C:1]([O:5][C:6]([N:8]1[C:16]2[C:11](=[CH:12][C:13]([C:17]3[S:19][CH:21]=[C:22]([C:23]([O:25][CH2:26][CH3:27])=[O:24])[N:18]=3)=[CH:14][CH:15]=2)[CH:10]=[CH:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]To a solution of 5-thiocarbamoyl-indole-1-carboxylic acid tert-butyl ester (13.16 g, 47.6 mmol) and 250 mL of EtOH was added ethyl bromopyruvate (6.05 mL, 48.2 mmol). The resulting solution was stirred at 60° C. for 1.5 h, then concentrated in vacuo. The resulting solid was purified by flash chromatography on silica gel using 5% EtOAc/hexane→80% EtOAc/hexane→CH2Cl2 as the eluant to give a white solid. MS m/z: 373 (M+1). Calc'd for C19H20N2O4S-372.44.
Loading…