“…When the reaction was shown to be complete by TLC examination, but crystallization did not occur spontaneously, the solution was diluted with a 1:1 diethyl ether/benzene mixture and extracted with saturated aqueous sodium bicarbonate solution (2 X 50 mL), once with water (50 mL), and once with saturated aqueous sodium chloride solution (50 mL). The organic layer was dried (MgS04), and the solvent was removed in vacuo to leave a solid mass, which was recrystallized from methanol, yielding 76% of colorless needles: mp 138.5-139.5 °C; IR (CC14) v 2942, 2847,1612,1510,1462,1439,1250,1225,1199,1117,1070,1022,945 cm'1; NMR (CDC13) 8 1.81-2.10 (m, 2 ), 2.45-2.91 (m, 4 H), 3.85 (s, 6 ), 6.50 (s, 1 ), 6.90-7.20 (m, 4 ), 7.91 (s, 1 H); 13C NMR (CDClg) 8 20.77,29.44,42.35,56.22,71.91,112.04,113.77, 122.27,125.83,127.04,131.20,138.22,147.58,149.92; MS m/e 330 (100), 302 (62), 297 (46), 287 (33), 266 (24), 221 (14), 190 (20), 189 (45), 115 (17), 77 (13); UV (THF) X,^2 94 (log e = 3.82), 241 (log e 4.6), Xmax/ (log « = 4.4). Anal.…”