Acetaldehyde → 1H-Indolamine

Participants

Reaction Steps

Crude 2-methyl-5-(pyrrolidin-3-yloxy)-1H-indole-3-carboxylic acid benzyl ester, hydrochloride (0.075 g, 0.194 mmol, 1 eq) was suspended in methanol (5 mL). Acetaldehyde (0.028 mL, 0.5 mmol, 2.6 eq) was added followed by the addition of sodium cyanoborohydride (0.032 g, 0.5 mmol, 2.6 eq). The reaction mixture was kept at pH 6 and stirred at room temperature. After 24 hours, the reaction was quenched with aqueous sodium bicarbonate, extracted several times with CH2Cl2. The combined organic layers were dried over sodium sulfate, loaded on silica gel and chromatographed (ethyl acetate/methanol/triethylamine 87/10/3). Impure product was further purified by reverse-phase prep-HPLC 10-100% Acetonitrile/water, 0.1% TFA. 0.008 g (10% yield) of the indole-amine was obtained as a brown semisolid: LC/MS (ESI+) 379 (M+1), Anal. (C23H26N2O3.TFA.1.0H2O) C, H, N.

Provenance & Evidence