Reaction Steps
A solution mixture of 3a (0.12 g, 0.55 mmol), 5 (0.2 g, 0.66 mmol) and piperidine (0.1 mL) in ethanol (35 mL) was heated to reflux overnight. After cooling down to room temperature, the organic solvent was removed. The residue was purified by recrystallization from methanol to afford SLOH (0.17 g) as red solid in 62% yield. 1H NMR (400 MHz, DMSO-d6) δ 9.20 (d, J=6.4 Hz, 1H), 9.15 (d, J=8.8 Hz, 1H), 8.87 (s, 1H), 8.56 (d, J=9.2 Hz, 1H), 8.52 (d, J=6.4 Hz, 1H), 8.40 (m, 2H), 8.24 (m, 2H), 8.13 (d, J=8.8 Hz, 1H), 8.05 (t, J=7.6 Hz, 1H), 7.78 (d, J=8.8 Hz, 1H), 7.71 (d, J=8.4 Hz, 1H), 7.52 (t, J=8.0 Hz, 1H), 7.31 (t, J=7.6 Hz, 1H), 5.27 (t, J=5.6 Hz, 1H), 5.05 (t, J=4.8 Hz, 2H), 4.64 (t, J=4.8 Hz, 2H), 3.94 (m, 2H), 3.84 (t, J=5.2 Hz, 2H), 3.47 (m, 2H), 3.31 (m, 2H), 3.11 (s, 3H). 13C NMR (400 MHz, DMSO-d6) δ 153.3, 147.8, 145.0, 142.1, 140.9, 138.1, 134.7, 128.7, 127.1, 126.8, 126.7, 126.5, 122.8, 122.2, 121.7, 120.3, 119.8, 119.2, 116.3, 114.8, 110.4, 110.3, 71.2, 69.8, 68.8, 58.9, 58.5, 58.0, 42.9. HRMS (MALDI-TOF) m/z Calcd for C30H31N2O3 467.2342. Found 467.2340 [M+]. Calcd for C30H31ClN2O3: C, 71.53; H, 6.21; N, 5.57. Found: C, 71.04; H, 6.23; N, 5.36.