Reaction Steps
To a mixture of 4-(4-methoxybenzoyl)piperidine hydrochloride (2.00 g, 7.82 mmol, 1.0 eq) and 5-(methoxycarbonyl)pyridine-2-carboxylic acid (1.42 g, 7.82 mmol, 1.0 eq) in dimethylformamide (55 mL) was added triethylamine (2.72 mL, 19.55 mmol, 2.5 eq) followed by HATU (2.97 g, 7.82 mmol, 1.0 eq). The reaction was stirred at room temperature for 4 hours before partitioning between EtOAc (250 mL) and water-NaHCO3 (1:1, 200 mL). The organics were further washed with brine (150 mL), water (150 mL) and brine (150 mL), dried (Na2SO4) and concentrated under reduced pressure. Column chromatography (silica, 4-5% MeOH—CH2Cl2) yielded the coupled product (2.39 g, 80%) as a white foam; 1H nmr (CDCl3) δ 9.08 (1H, m, pyH-6), 8.29 (1H, dd, J 8.5, 2.0 Hz, pyH-4), 7.84 (2H, d, J 9.0 Hz, 2H of C6H4OCH3), 7.60 (1H, d, J 8.0 Hz, pyH-3), 6.84 (2H, d, J 9.0 Hz, 2H of C6H4OCH3), 4.60 (1H, m, 1H of BzpipH-2, H-6), 3.87 (3H, s, 1×OCH3), 3.82 (1H, m, 1H of BzpipH-2, H-6), 3.77 (3H, s, 1×OCH3), 3.46 (1H, m, BzpipH-4), 3.19 (1H, ddd, J 14.0, 10.0, 4.0 Hz, 1H of BzpipH-2, H-6), 3.02 (1H, m, 1H of BzpipH-2, H-6), 1.95-1.90 (1H, m, 1H of BzpipH-3, H-5), 1.83-1.79 (3H, m, 3H of BzpipH-3, H-5); 13C nmr (CDCl3) δ 199.9, 166.6, 165.0, 163.5, 157.7, 149.6, 138.1, 130.5, 128.5, 126.3, 123.1, 113.9, 55.4, 52.5, 46.6, 42.6, 41.8, 28.8, 28.4; m/z: 383 [M+H]+(found [M+H]+, 383.1515, C21H22N2O5 requires [M+H]+383.1602).
