Acetic Anhydride → N-(1-ethyl-3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-6-yl)-acetamide
Reaction equation
[NH2:1][C:2]1[CH:10]=[C:9]2[C:5]([C:6]([CH3:15])([CH3:14])[C:7](=[O:13])[N:8]2[CH2:11][CH3:12])=[CH:4][CH:3]=1.[C:16](OC(=O)C)(=[O:18])[CH3:17]>>[CH2:11]([N:8]1[C:9]2[C:5](=[CH:4][CH:3]=[C:2]([NH:1][C:16](=[O:18])[CH3:17])[CH:10]=2)[C:6]([CH3:14])([CH3:15])[C:7]1=[O:13])[CH3:12]Participants
3
Procedure
A solution of 6-amino-1-ethyl-3,3-dimethyl-1,3-dihydro-indol-2-one (5.05 g, 24.72 mmol) in acetic anhydride (80 ml) was stirred at room temperature for 4 h. The mixture was poured onto ice water (150 ml), allowed to warm to room temperature and was stirred again for 2 h. After extraction with ethyl acetate (3×100 ml), the combined organic layers were washed with sat. NaHCO3-solution (3×100 ml), brine (100 ml) and dried over sodium sulfate. After removal of the solvent the crude product was purified by column chromatography on silica gel (ethyl acetate/n-heptane 1:1) yielding 5.6 g (91%) N-(1-ethyl-3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-6-yl)-acetamide as light yellow solid.