1-Acetyl-7-nitro-5-ethoxycarbonylmethyl-4,6-dimethylindoline → 1-Acetyl-7-amino-5-ethoxycarbonylmethyl-4,6-dimethylindoline

Participants

Reaction Conditions

Reaction Steps

In a 100-ml autoclave, 1-acetyl-7-nitro-5-ethoxycarbonylmethyl-4,6-dimethylindoline (5.0 g) obtained in Example 5 and 7.5% palladium on charcoal (wet, 3.76 g) were suspended in ethanol (50 ml). After degassing with nitrogen for 3 times (5 kg/cm2 for each) and replacing nitrogen with hydrogen for 3 times (5 kg/cm2 for each) successively, the resulting mixture was stirred for 2 hours at 55° C. under a pressurized hydrogen atmosphere (5 kg/cm2). The reaction mixture was filtered to remove palladium on charcoal, which was washed with ethanol (50 ml). The filtrate and washing were combined and concentrated under reduced pressure to give a fraction of the title compound. Furthermore, palladium on charcoal separated above was suspended in dichloromethane (50 ml), and after stirring at room temperature, the catalyst was removed by filtration and washed with dichloromethane (25 ml). The filtrate and washing were combined and concentrated under reduced pressure to give another fraction of the title compound. The title compound (4.1 g, yield: 90%) was obtained by combining two fractions of the title compound obtained above.

Provenance & Evidence