Hydrochloric Acid → [5-(2-methoxy-ethoxy)-1H-indol-ylmethyl]-dimethyl-amine

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Reaction Steps

A solution of 5-(2-methoxy-ethoxy)-indole (2.06 g, 11.0 mmol) in acetic acid (7 ml) and 40% aqueous dimethylamine (2.1 ml) is cooled to 0° C., and 36% aqueous formaldehyde (1.38 ml) (pre-cooled to 0° C.) is added drop wise. The mixture is stirred at room temperature overnight, 2 M hydrochloric acid is added, and the mixture is washed with dichloromethane. The aqueous layer is made alkaline with 10% NaOH, and is extracted with dichloromethane. The combined organic layer is washed with water, is dried and concentrated. The residue is purified by column chromatography (dichloromethane-methanol, 4:1→dichloromethane-methanol-water-aqueous ammonia, 10:20:1:1) to afford [5-(2-methoxy-ethoxy)-1H-indol-ylmethyl]-dimethyl-amine (2.42 g, 90%). M.p. 163-164° C. (from toluene-N,N-dimethylformamide).

Provenance & Evidence