Acetic Acid → 2-(Cyclopropylamino)-1-methyl-1H-indole

Participants

Reaction Steps

To a solution of 1-methylindole-2-carboxaldehyde (1.5 g, 10 mmole), cyclopropylamine (1.14 g, 20 mmole), and glacial acetic acid (0.6 mL, 10 mmole) in MeOH (30 mL) was added NaBH3CN (0.69 g, 11 mmole). The reaction was stirred at RT overnight, then was concentrated in vacuo. The residue was diluted with 10% NaOH and extracted with CH2Cl2. The combined organic extracts were washed with brine, dried over MgSO4, and concentrated. Flash chromatography on silica gel (3% MeOH/CH2Cl2) gave the title compound (1.3 g, 65%) as a semi-solid: MS (ES) m/e-201 (M+H)+.

Provenance & Evidence