Hydrochloric Acid → 2-(3-methylamino-propyl)-1H-indole-5-carboxylic acid (3,4-dimethoxy-phenyl)-amide

A 250 round bottom flask was charged with tert-butyl 3-(5-(3,4-dimethoxyphenylcarbamoyl)-1H-indol-2-yl)propyl(methyl)carbamate (2.75 g, 5.88 mmol), dichloromethane (32 mL), and 1M hydrochloric acid in diethyl ether (32 mL) and the resulting mixture stirred for 2.5 h. The resulting mixture was then concentrated in vacuo, the residue triturated with diethyl ether, and placed under high vacuum to yield 2-(3-methylamino-propyl)-1H-indole-5-carboxylic acid (3,4-dimethoxy-phenyl)-amide. MS (ES+) 368 (M+1); HPLC: Kromasil C18 column (50×2 mm; 3.5μ), gradient 10-90% (MeCN+0.16% TFA) in (water+0.2% TFA) over 4 min, tR=2.72 min.