Reaction Steps
To a solution of Compound 281a (7.10 g, 26.2 mmol) in dry methanol (200 mL) was added Dowex 1×8-200 hydroxide form (1.00 g) and the resulting mixture was heated at 60° C. for 24 hours. The warm reaction mixture was filtered and the filtrate was distilled until 100 mL remained. Ethyl ether (100 mL) was added to the residue and the resulting solution was allowed to stand in the refrigerator at zero degrees C for 16 hours. The crystalline precipitate was filtered off, washed with ethyl ether (50 mL) to give 5.03 g (84 percent) of Compound 282a: white crystalline solid; mp 189.5°-190.5° C.; Rf =0.21 (silica, ethyl ether); IR (CHCl3) νmax 3156, 2931, 1621, 1508 cm-1 ; 1H NMR (300 Mz, CDCl3) δ 8.45 (s, 1 H, H6), 7.96 (d, J=9.2 Hz, 1 H, H4), 7.50 (d, J=2.6 Hz, 1 H, H3), 7.31 (dd, J=9.2, 2.6 Hz, 1 H, H1), 5.37 (br s, 1 H, H10), 3.97 (s, 3 H, OCH3), 2.97-2.75 (m, 2 H, H7), 2.75-2.30 (br s, 1 H, OH), 2.30 (br d, J=10.6 Hz, 1 H, H9), 2.07-1.96 (m, 3 H, H8 and H9); 13C NMR (125 Mz, DMSO-d6) δ 157.1, 149.7, 142.5, 140.2, 130.2, 129.7, 128.1, 119.7, 103.0, 61.0, 55.3, 31.8, 26.6, 16.7; MS (FAB+) m/e (rel intensity) 230 (M+H, 100), 212 (10);HRMS for C14H16NO2 (M+H), calcd 230.1181, found 230.1189. Anal. Calcd for C14H15NO2 : C, 73.34; H, 6.59; N, 6.11. Found: C, 73.16; H, 6.73; N, 6.08.
