“…It was cooled overnight and the precipitated solid formed was recrystallized from ethanol to obtain the pure product as yellow crystals (87%); m.p. : 122-124 °C; IR (KBr) " m = 3,238, 2,937, 1,766, 1,730, 1,704, 1,681, 1,598, 1,481, 1,409, 1,367, 1,305, 1,232, 1,100, 1,020 cm -1 ; 1 H NMR (500.1 MHz, CDCl 2), 417 (6), 350 (6), 308 (4), 290 (5), 266 (9), 222 (17), 204 (20), 191 (8), 178 (25), 161 (15), 132 (17), 105 (100).…”