Formaldehyde → 1-(1-Ethyl-1H-pyrrol-2-yl)-N,N-dimethylmethanamine

A mixture of 35% aqueous formaldehyde solution (9 ml, 105 mmol) and dimethylamine hydrochloride (9.0 g, 110 mmol) was added to 1-ethylpyrrole (10.0 g, 105 mmol) with stirring under ice-cooling over a 90-minute interval, and then the resulting mixture was stirred at room temperature for 6 hours. After stirring, 10% aqueous sodium hydroxide solution (150 ml) was added to the reaction mixture, and the resulting mixture was extracted with ether. The extract was washed with saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. After filtration, the solvent was removed in vacuo, and the residue was purified by chromatography on a silica gel column using a mixed solvent of dichloromethane and methanol (9:1) as the eluent to afford 2-(N,N-dimethylaminomethyl)-1-ethylpyrrole (15.6 g, yield: 97%).