Hydrochloric Acid → 6-Chloro-2,3,4,9-tetrahydro-1H-carbazol-1-amine

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Reaction Conditions

Reaction Steps

To a solution of 6-chloro-2,3,4,9-tetrahydro-1H-carbazol-1-one (500 mg, 2.3 mmol) and ammonium acetate (1.8 g, 23 mmol) in methanol (9 mL) was added sodium cyanoborohydride (720 mg, 11.5 mmol). After heating at 60° C. for 15 hours, the mixture was cooled and treated with concentrated hydrochloric acid until pH=1. The organics were removed under reduced pressure and the resulting precipitate was collected by filtration, dissolved in ethyl acetate and methanol, and washed with saturated aqueous sodium carbonate. The phases were separated and the organic phase was concentrated to yield 6-chloro-2,3,4,9-tetrahydro-1H-carbazol-1-amine (260 mg, 52% yield) as a light brown solid. 1H-NMR (DMSO-d6): δ 10.90 (s, 1H), 7.34 (m, 1H), 7.27 (d, 1H), 6.97 (dd, 1H), 3.90 (t, 1H), 2.54 (m, 2H), 2.04-1.89 (m, 2H), 1.66 (m, 1H), 1.50 (m, 1H); MS m/z 221 (M+1).

Provenance & Evidence