“…1 H NMR (400 MHz, CD 3 OD) δ 6.92−6.85 (m, 2H), 6.81 (d, J = 9.5 Hz, 1H), 4.28 (s, 2H), 3.99 (t, J = 6.2 Hz, 2H), 3.82 (s, 3H), 3.24−3.16 (m, 2H), 2.22 (t, J = 7.4 Hz, 2H), 1.88−1.76 (m, 2H), 1.70−1.52 (m, 6H), 1.33−1.24 (m, 10H), 0.89 (t, J = 6.8 Hz, 3H). 13 (21). Following the general procedure, compound 5 (50 mg, 0.11 mmol), ammonia (5 mL, 7.0 M solution in methanol), and MeOH (2 mL) were used to prepare compound 13.…”