1-(3,3-Dimethyl-6-nitroindolin-1-yl)ethanone → 1-(6-Amino-3,3-dimethylindolin-1-yl)ethanone

Participants

Reaction Conditions

Reaction Steps

A Parr hydrogenation unit was charged with 1-(3,3-dimethyl-6-nitroindolin-1-yl)-ethanone (450 g, 1.92 mol), THF (1.8 L), and 10% Pd/C (20.3 g). The unit was purged with nitrogen twice then agitated. The unit was pressurized with 50 psi hydrogen and the agitation was continued until absorption ceased. Hydrogen absorption was exothermic. The temperature was maintained below 50° C. during the reaction. The reaction was monitored by GC. After 8 min, the unit was purged with nitrogen. The mixture was filtered through a Celite™ pad and washed the pad with THF (100 mL×1). The filtrate was concentrated under reduced pressure to ¼ total volume and cooled to 0° C. To the mixture was added heptane (800 mL×1) and the mixture was stirred at 0° C. for 45 min. The resulting precipitate was collected by filtration, washed the solid with heptane (150 mL×1), and dried at 50° C. under reduced pressure to give 1-(6-amino-3,3-dimethylindolin-1-yl)ethanone.

Provenance & Evidence