p-Fluorophenethylamine → trans 2-pentenoic Acid [2-(4-fluorophenyl)ethyl]amide

Participants

Reaction Steps

A solution of trans-2-pentenoic acid (7.62 g, 76.2 mmol) in tetrahydrofuran (350 mL) was stirred at −15° C. and treated with N-methylmorpholine (8.37 mL, 76.2 mmol). After 10 minutes, isobutyl chloroformate (9.87 mL, 76.2 mmol) was added. After 10 minutes, a precipitate had formed. A solution of 2-(4-fluorophenyl)ethylamine (10.6 g, 76.2 mmol) in tetrahydrofuran (50 mL) was added slowly, and the mixture was stirred at room temperature, and the residue was dissolved in ethyl acetate. The then with saturated aqueous sodium bicarbonate, then was dried over sodium sulfate and concentrated. The residue was recrystallized from ethyl acetate/hexane to provide white crystals (11.69 g, 69%). 1H NMR (300 MHz, CDCl3) δ7.17 (m, 2H), 7.01 (t, J=9 Hz, 2H), 6.88 (dt, J=15, 7 Hz, 1H), 5.72 (dt, J=15, 2 Hz, 1H), 5.61 (bs, 1H), 3.56 (m, 2H), 2.83 (t, J=7 Hz, 2H), 2.20 (m, 2H), 1.05 (t, J=7 Hz, 3H). Mass spec (ES+) m/z 221.9 (M+H+, 100%).

Provenance & Evidence