Tetrahydro-beta-carboline → 2,3,4,4a,9,9a-hexahydro-1H-pyrido[3,4-b]indole

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Reaction Steps

To a solution of 2,3,4,9-tetrahydro-1H-beta-carboline (0.100 g, 0.581 mmol) in TFA (1 mL) was added sodium cyanoborohydride (0.109 g, 1.74 mmol) and the reaction mixture was stirred at ambient temperature for about 16 h. The reaction mixture was concentrated in vacuo and the residue was partitioned between water (25 mL) and dichloromethane (50 mL). The organic layer was separated and the aqueous layer was further extracted with dichloromethane (2×50 mL). The combined organic extracts were dried over magnesium sulfate, and evaporated under reduced pressure. The residue was purified by using preparative RP-HPLC (Rainin C18, 8 mm, 300 Å, 35 cm; 5-100% acetonitrile—0.1M ammonium acetate over 20 min, 100% acetonitrile hold 10 minutes, 21 mL/min) to give 2,3,4,4a,9,9a-hexahydro-1H-beta-carboline (0.073 g, 0.42 mmol) as a brown oil; RP-HPLC (Table 1, Method a) Rt 1.35 min; m/z: (M+H)+ 175.

Provenance & Evidence