Sodium Carbonate → 2-(tert-Butyl)-6-nitroindoline

Reaction equation

[C:1]([CH:5]1[CH2:13][C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[NH:6]1)([CH3:4])([CH3:3])[CH3:2].[N+:14]([O-])([O-:16])=[O:15].[K+].C([O-])([O-])=O.[Na+].[Na+]>OS(O)(=O)=O>[C:1]([CH:5]1[CH2:13][C:12]2[C:7](=[CH:8][C:9]([N+:14]([O-:16])=[O:15])=[CH:10][CH:11]=2)[NH:6]1)([CH3:4])([CH3:2])[CH3:3]

Participants

Procedure

To a solution of the mixture of 2-tert-butyl-2,3-dihydro-1H-indole and 2-ten-butyl-1H-indole (9.7 g) in H2SO4 (98%, 80 mL) was slowly added KNO3 (5.6 g, 55.7 mmol) at 0° C. The reaction mixture was stirred at room temperature for 1 h, carefully poured into cracked ice, basified with Na2CO3 to pH-8 and extracted with ethyl acetate. The combined extracts were washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by column chromatography to give 2-tert-butyl-6-nitro-2,3-dihydro-1H-indole (4.0 g, 32% over 2 steps).