Sodium borohydride → 5-amino-2-tert-butyl-1H-indole-7-carbonitrile

Participants

Reaction Steps

To a solution of crude product 2-tert-butyl-5-nitro-1H-indole-7-carbonitrile (0.87 g, 3.6 mmol) in MeOH (10 mL) was added NiCl2.6H2O (1.8 g, 7.2 mmol) at −5° C. The reaction mixture was stirred for 30 min, then NaBH4 (0.48 g, 14.32 mmol) was added to the reaction mixture at 0° C. After 5 min, the reaction mixture was quenched with water, filtered and extracted with EtOAc. The combined organic layers were dried over Na2SO4 and concentrated under vacuum to obtain the crude product, which was purified by column chromatography (5-20% EtOAc in petroleum ether) to obtain 5-amino-2-tert-butyl-1H-indol-7-carbonitrile (470 mg, 32% over two steps). 1H NMR (400 MHz, CDCl3) δ 8.25 (s, 1 H), 7.06 (d, J=2.4 Hz, 1 H), 6.84 (d, J=2.4 Hz, 1 H), 6.14 (d, J=2.4 Hz, 1 H), 3.57 (br s, 2 H), 1.38 (s, 9 H). MS (ESI) m/z: 214 (M+H+).

Provenance & Evidence