Acetic Acid → N-Ethyl-4-(5-nitro-1H-indol-3-yl)cyclohex-3-enamine

Participants

Reaction Steps

A solution of compound 79 (1.0 g, 3.902 mmol) in dry 1,2-dichloroethane (10 mL) was treated with ethylamine hydrochloride (0.31 g, 3.902 mmol), glacial acetic acid (0.22 mL, 3.902 mmol) and NaBH(OAc)3 (1.24 g, 5.853 mmol) at room temperature and the resulting mixture was stirred for overnight (14 h). The reaction was diluted with 1 N NaOH (30 mL) and product was extracted into ethyl acetate (2 50 mL). The combined ethyl acetate layer was washed with brine (20 mL) and dried (Na2SO4). Solvent was evaporated and crude was purified by column chromatography (2 M NH3 in methanol: CH2Cl2, 1:9) to obtain compound 117 (1.08 g, 97%) as a dark yellow solid. mp 177-179° C.; 1H NMR (DMSO-d6) δ: 1.03 (t, 3H, J=6.9 Hz), 1.39-1.52 (m, 2H), 1.94-2.00 (m, 2H), 2.40-2.80 (m, 3H), 3.16 (s, 2H), 4.07 (brs, 1H), 6.13 (s, 1H), 7.54 (d, 1H, J=9.0 Hz), 7.62 (s, 1H), 8.00 (dd, 1H, J=2.4, 9.0 Hz), 8.67 (d, 1H, J=2.4 Hz), 11.83 (brs, 1H); ESI-MS m/z (%): 286 (MH+, 100).

Provenance & Evidence