Triethylamine → (4-Methoxy-benzyl)-(2-thiophen-3-yl-ethyl)-amine Hydrochloride

Participants

Reaction Conditions

Reaction Steps

A solution of 2-(3-thienyl)ethanamine hydrochloride (1.0 g, 6.1 mmol), 4-methoxybenzaldehyde (0.74 mL, 6.1 mmol), and triethylamine (1.7 mL, 12.2 mmol) in ethanol (60 mL) was stirred at 25° C. for 5 h. The reaction mixture was cooled to 0° C. and sodium borohydride (289 mg, 7.6 mmol) was added portionwise over 30 min. The reaction mixture was warmed to 25° C. and stirred for 1 h. The reaction mixture was diluted with acetone (5 mL) dropwise and concentrated to a residue that was dissolved in CH2Cl2 (10 mL) and 1.0 N NaOH (10 mL). The aqueous layer was separated and extracted with CH2Cl2 (10 mL). The combined organic extracts were washed with brine (10 mL), dried with Na2SO4, filtered, and concentrated to give a crude oil which was purified using flash column chromatography (30% ethyl acetate/hexane →90% EtOAc/hexane). The fractions containing the amine were acidified with 2 N HCl in 1,4-dioxane to yield 4.11-A as a white solid (1.3 g, 78%). 1H NMR (500 MHz, CD3OD): δ 7.46–7.43 (m, 3H), 7.26–7.25 (m, 1H), 7.07–7.06 (m, 1H), 7.05–7.02 (m, 2H), 4.18 (s, 2H), 3.85 (s, 3H), 3.31–3.28 (m, 2H), 3.08 (dd, J=8.3, 7.8 Hz, 2H); LCMS found for C14H 18NOS (M+H)+: m/z=248.

Provenance & Evidence