Reaction Steps
Amine 20 (1.70 g, 0.0058 mol) was dissolved in anhydrous toluene (100 mL) followed by the addition of phthalic anhydride (2.61 g, 0.018 mol), and the mixture was refluxed with Dean-Stark trap overnight. The solution was then cooled, washed with 1 N NaOH (3×50 mL) and water. The organic layer was collected, dried (Na2SO4) and the solvent removed under reduced pressure yielding crude product. The crude product was purified by flash chromatography (30% EtOAc/hexanes on neutral Al2O3 Brockman activity II-III) to afford 2.22 g (90%) of 21 as a white solid: LCMS (ESI): m/z 419.9 (M+H)+; 1H NMR (CDCl3, 300 MHz) δ 7.80-7.83 [m, 2H], 7.68-7.71 [m, 2H], 7.23-7.27 [m, 3H], 6.77-6.79 [m, 1H], 4.81 [m, 1H], 3.85 [s, 3H], 3.28 [t, J=12 Hz, 1H], 3.01 [d, J=12 Hz, 1H], 2.83-2.85 [m, 1H], 2.65-2.81 [m, 1H], 2.40-2.47 [m, 2H], 2.37 [s, 3H], 2.16-2.20 [m, 1H], 1.89 [ddd, J1=J2=15 Hz, J3=6 Hz, 1H], 1.48-1.58 [m, 3H], 1.33-1.39 [m, 1H], 1.26 [s, 3H]; 13CNMR (CDCl3, 300 MHz) δ 168.8, 159.2, 148.4, 134.1, 132.4, 128.7, 123.3, 121.8, 116.0, 111.0, 64.8, 55.5, 52.9, 47.8, 47.2, 43.8, 36.7, 35.6, 34.1, 26.7, 24.3.
