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

Temperature

0 °C

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.

1. customThe unit was purged with nitrogen twice
2. customthe agitation was continued until absorption
3. customHydrogen absorption
4. temperatureThe temperature was maintained below 50° C. during the reaction
5. customthe unit was purged with nitrogen
6. filtrationThe mixture was filtered through a Celite™ pad
7. washwashed the pad with THF (100 mL×1)
8. concentrationThe filtrate was concentrated under reduced pressure
9. additionTo the mixture was added heptane (800 mL×1)
10. stirringthe mixture was stirred at 0° C. for 45 min
11. filtrationThe resulting precipitate was collected by filtration
12. washwashed the solid with heptane (150 mL×1)
13. customdried at 50° C. under reduced pressure

ORD record

ord-6969587d0bba449c8184df7e7add0bc2

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08765940B2