Acetic Acid → 1-(4-Bromothiophen-2-yl)-N,N-dimethylmethanamine

Participants

Reaction Steps

To a solution of 4-bromo-2-thiophene carboxaldehyde (5 g, 26.2 mmol) in 1,2-dichloroethane (50 mL) is added sodium triacetoxyborohydride (8.3 g, 39.3 mmol) and dimethylamine (14.5 mL, 28.8 mmol) followed by acetic acid (1.55 mL, 39.3 mmol). The mixture is stirred at room temperature for 2 hours. The insoluble is filtered and washed with diethyl ether. The mother liquor is concentrated. The resulting thick oil that is chromatographed through silica gel (dichloromethane-1.0M ammonia in methanol, 95:05 to 90:10 as eluant) to afford an orange oil. It is dissolved in dichloromethane and was washed with a saturated aqueous sodium bicarbonate solution. The organic layer is dried over magnesium sulfate and concentrated to produce (4-bromo-thiophen-2-ylmethyl)-dimethyl-amine [4.08 g, 71%, intermediate (1)] as an orange oil. LC/MS: RT=0.63 minutes, 219.99 m/e (M+H).

Provenance & Evidence