Trifluoroacetic acid → 2-aminoethyl acetate TFA-salt

Participants

Reaction Steps

A solution was made containing ethanolamine (36.5 ml, 0.6 mol) in chloroform (1000 ml). The Boc2O (13.1 g, 60 mmol) dissolved in chloroform (600 ml) was slowly added dropwise at 0° C. over a 6-hours period (the temperature was maintained all over this period). The reaction was allowed to reach room temperature and was stirred overnight. The organic layer was washed with water (2×500 ml), brine and dried over magnesium sulfate before being concentrated in vacuo. The desired product (9.5 g,>95%) was isolated as a colourless oil and was used without further purification. A solution was made containing the Boc-ethanolamine (1.92 g, 12 mmol) with potassium carbonate (5 g, 36 mmol) in DCM (40 ml). Acetyl chloride (30 ml, 0.42 mol) was added and the reaction stirred for 6 hours at room temperature. The excess of acetyl chloride was removed in vacuo and the crude dissolved in DCM (100 ml). The organic layer was washed with water (50 ml), brine and dried over magnesium sulfate before being concentrated in vacuo. The desired product (1.86 g, 77%) was isolated as a colourless oil and was used without further purification. A solution was made containing the O-acyl, Boc-ethanolamine (1.65 g, 8.1 mmol) in DCM (20 ml) and TFA (20 ml) was added. After one hour at room temperature, the solvent was removed in vacuo. The crude was concentrated from methanol (2–3 times) and from DCM (2–3 times) to give the expected compound (1.75 g, quant.) as an oil used without further purification.

Provenance & Evidence