Reaction Steps
A mixture of Compound 275 (57.17 g, 287 mmol) , 2-nitrobenzyl bromide (68.19 g, 316 mmol), powdered potassium carbonate (142.0 g, 1.03 mol) and tetra-n-butylammonium iodide (3.18 g, 8.61 mmol) in dry DMF (400 mL) was stirred at 25° C. for 3 hours and then poured into a mixture of ethyl ether (200 mL), dichloromethane (1500 mL), and water (200 mL) with stirring. After allowing this mixture to settle, the aqueous layer was discarded. The organic layer was washed with water (3×1500 mL), dried (MgSO4), and filtered through a 8 cm×8 cm plug of silica with rinsing with ethyl ether (300 mL). The combined filtrates were evaportated in vacuo, and the residue was purified by recrystallization from chloroform-ethyl ether to give 90.41 g (94 percent) of Compound 276: off-white crystalline solid; mp 153°-154° C. Rf=0.48 (silica, 40 percent ethyl acetate in dichloromethane); IR (CHCl3) νmax 2939, 1619, 1526, 1508, 1433, 1342 cm-1 ; 1H NMR (300 MHz, CDCl3) δ 8.50 (s, 1 H, H6), 8.19 (dd, J=7.4, 1.0 Hz, 1 H, aromatic), 7.99 (d, J=9.1 Hz, 1 H, H4), 7.97 (dd, J=7.4, 1.0 Hz, 1 H, aromatic), 7.71 (td, J=7.4, 1.0 Hz, 1 H, aromatic), 7.52 (td, J=7.4, 1.0 Hz, 1 H, aromatic), 7.39 (dd, J=9.1, 2.8 Hz, 1 H, H3), 7.24 (d, J=2.8 Hz, 1 H, H1), 5.61 (s, 2 H, benzylic), 2.99 (t, J= 6.1 Hz, 2 H, H7 or H10), 2.88 (t, J=6.1 Hz, 2 H, H7 or H10), 2.01-1.84 (m, 4 H, H8 and H9); --C NMR (125 MHz, CDCl3) δ 156.0, 150.3, 146.9, 142.4, 140.0, 134.0, 133.9, 133.4, 131.5, 130.1, 128.5, 128.4, 124.9, 119.8, 102.7, 66.7, 27.1, 24.9, 22.3, 22.2; MS (FAB+) m/e (rel intensity) 335 (M+H, 100), 200 (13); HRMS for C20H19N2O3 (M+H), calcd 335.1396, found 335.1394.
