Sodium Hydroxide → 2-Methyl-1H-indole-3-ethylamine

Participants

Reaction Conditions

Reaction Steps

A suspension of LiAlH4 (17 g, 445 mmol) in dry THF (1000 mL) is cooled to 0° C. and 2-methylindole-3-glyoxylamide (30 g, 148 mmol) is added in portions over 30 minutes. The mixture is stirred at room temperature for 30 minutes and then maintained at reflux for 3 hours. The reaction is cooled to 0° C. and treated with H2O (17 ml), 15% NaOH (aq., 17 ml) and H2O (51 ml). The mixture is treated with MgSO4, filtered and the filtrate evaporated to give 2-methyltryptamine which is dissolved in MeOH. Methyl 4-formylcinnamate (16.9 g, 88.8 mmol) is added to the solution, followed by NaBH3CN (8.4 g) and AcOH (1 equiv.). After 1 hour the reaction is diluted with NaHCO3 (aq.) and extracted with EtOAc. The organic extracts are dried (MgSO4), filtered and evaporated. The residue is purified by chromatography to give 3-(4-{[2-(2-methyl-1H-indol-3-yl)-ethylamino]-methyl}-phenyl)-(2E)-2-propenoic acid methyl ester. The ester is dissolved in MeOH, 1.0 M HCl/dioxane (1-1.5 equiv.) is added followed by Et2O. The resulting precipitate is filtered and the solid washed with Et2O and dried thoroughly to give 3-(4-{[2-(2-methyl-1H-indol-3-yl)-ethylamino]-methyl}-phenyl)-(2E)-2-propenoic acid methyl ester hydrochloride. 1.0 M NaOH (aq., 85 mL) is added to an ice cold solution of the methyl ester hydrochloride (14.9 g, 38.6 mmol) and HONH2 (50% aq. solution, 24.0 mL, ca. 391.2 mmol). After 6 hours, the ice cold solution is diluted with H2O and NH4Cl (aq., 0.86 M, 100 mL). The resulting precipitate is filtered, washed with H2O and dried to afford N-hydroxy-3-[4-[[[2-(2-methyl-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide (m/z 350 [MH+]).

Provenance & Evidence