“…Upon the removal of THF from the organic phase on a rotary evaporator, the precipitate was collected and purified on a silica gel column with chloroform as eluent to obtain 8 as colorless powders (1.03 g, 84% yield). 1 H NMR (500 MHz, CDCl 3 ) *: 8.20~8.10 (m, 6H), 8.08 (d, J = 7.5 Hz, 4H), 8.01~7.97 (m, 6H), 7.95 (d, J = 7.5 Hz, 2H), 4.19 (t, J = 6.5 Hz, 4H), 3.39 (s, 2H), 3.29 (t, J = 7.5 Hz, 4H), 1.87~1.86 (m, 4H), 1.79~1.76 (m, 4H) ppm; 13 3073 9% 13…”