Stannous chloride dihydrate → HCID 58851477, compound

Participants

Reaction Conditions

Reaction Steps

To an ice-cold solution of 1-(6-aminoindolin-1-yl)-2,2,2-trifluoroethanone (7.00 g, 30.4 mmol) in 6N HCl (50 mL) was dropwise added a solution of NaNO2 (2.10 g, 30.4 mmol) in H2O (5 mL). The resulting slurry was stirred at 0° C. for 30 min. A solution of SnCl2.2H2O (11.5 g, 60.8 mmol) in conc. HCl (60 mL) was added dropwise and after the addition was complete the resulting slurry was stirred at RT for 2 h. The mixture was filtered and the resulting solid was redissolved in EtOH (200 mL). Pivaloyl acetonitrile (4.57 g, 36.5 mmol) was added and the solution was heated at reflux overnight. Water (100 mL) was added and the mixture was extracted with CH2Cl2 (3×100 mL), dried (MgSO4), concentrated and purified by recrystallization from ethyl acetate/hexanes to yield 1-(6-(5-amino-3-t-butyl-1 H-pyrazol-1-yl)indolin-1-yl)-2,2,2-trifluoroethanone (3.2 g, 30% yield) as a light-brown solid. 1H-NMR (400 MHz, acetone-d6): δ 8.49 (d, J=2.0 Hz, 1H), 7.51 (dd, J=8.4, and 2.0 Hz, 1H), 4.41 (t, J=8.2 Hz, 2H), 3.32 (t, J=8.2 Hz, 2H), 1.32 (s, 9H), pyrazolamine protons not observed; MS (ESI) m/z: 353.2 (M+H+).

Provenance & Evidence