Reaction Steps
Into a dry 1 L round-bottomed flask equipped with a magnetic stirrer was added (+)-pseudoephedrine (22.34 g, 135.22 mmol, 1.0 equiv), triethylamine (21.5 mL, 154 mmol, 1.14 equiv), and tetrahydrofuran (300 mL). The solution was cooled to 0° C. and hydrocinnamoyl chloride (25.08 g, 148.74 mmol, 1.1 equiv) in tetrahydrofuran (100 mL) was added via cannula over a 20 minute interval. After 30 minutes, the reaction was quenched with water. The amide was extracted from water (1 L) with ethyl acetate (400 mL, 120 mL, 120 mL), and the combined organic extracts were dried over sodium sulfate. After removal of the solvent under reduced pressure, a white solid was obtained, which was recrystallized from 2:1:1 ether/dichloromethane/hexanes (500 mL) affording the hydrocinnamide as white crystals (30.24 g, 75% yield): mp 102°-104° C.; 1H NMR (300 MHz, C6D6) δ7.0-7.4 (m, 5H), 4.59 (br, 1H), 4.48 (t, 1H, J=7.1 Hz), 4.20 (m, 1H), 4.01 (dd, 1H, J=8.4 Hz, 2.4 Hz), 3.66 (m, 1H), 3.15 (m, 2H), 2.93 (t, 2H, J=7.7 Hz), 2.79 (s, 3H), 2.49 (m, 2H), 2.13 (m, 2H), 2.02 (s, 3H), 0.92 (d, 3H, J=7.0 Hz), 0.49 (d, 3H, J=6.8 Hz); 13C NMR (75.5 MHz, CDCl3) δ174.3, 173.2, 142.2, 141.5, 141.3, 141.1, 128.6, 128.39, 128.36, 128.31, 128.29, 128.2, 127.6, 126.8, 126.4, 126.1, 125.9, 76.3, 75.3, 58.0, 36.1, 35.4, 32.3, 31.5, 31.1, 26.9, 15.2, 14.3; FTIR (neat film) cm-1 3374 (br, m), 3027 (m), 1621 (s), 1495 (m), 1454 (m), 1406 (m), 1118(m), 1048 (m), 753 (m), 701 (m); HRMS (FAB) Calcd for C19H24NO2 (MH+): 298.1808; Found: 298.1806.
