Reaction Steps
To a mixture of 6-(4-(4-methoxybenzoyl)piperidine-1-carbonyl)nicotinic acid (0.094 g, 0.257 mmol, 1.0 eq), and 3-trifluoromethyl-4-amino-1-Boc-piperidine (0.257 mmol, 1.0 eq) was added dimethylformamide (2.5 mL) and triethylamine (0.054 mL, 0.386 mmol, 1.5 eq). HATU (0.107 g, 0.283 mmol, 1.1 eq) was added and the reaction was stirred at room temperature for 14 hours and partitioned between EtOAc (120 mL) and NaHCO3-water (1:1, 120 mL). The organics were further washed with brine (100 mL), water (100 mL) and brine (100 mL), dried (Na2SO4) and concentrated under reduced pressure. MPLC (0→10% MeOH—CH2Cl2) yielded the coupled product (0.104 g, 68%) as a colourless oil; 1H nmr (CDCl3) δ 8.90 (1H, br s, pyH-6), 8.08 (1H, br d, J 7.0 Hz, pyH-4), 7.92 (2H, d, J 9.0 Hz, 2H of C6H4OMe), 7.50 (2H, m, pyH-3, NH), 6.94 (2H, d, J 9.0 Hz, 2H of C6H4OMe), 4.61 (2H, m, 1H of pipH-2, H-4, H-6, 1H of BzpipH-2, H-6), 3.86 (3H, s, OCH3), 3.86-3.74 (2H, m, 1H of pipH-2, H-4, H-6, 1H of BzpipH-2, H-6), 3.52 (1H, m, BzpipH-4), 3.52-3.38 (2H, m, 2H of pipH-2, H-4, H-6), 3.26-3.04 (1H, m, 1H of pipH-2, H-3, H-4, H-6), 3.22 (1H, m, 1H of BzpipH-2, H-6), 3.12 (1H, t, J 11.5 Hz, 1H of BzpipH-2, H-6), 2.76 (1H, m, 1H of pipH-2, H-3, H-4, H-6), 2.00 (1H, m, 1H of BzpipH-3, H-5), 1.90-1.65 (5H, m, pipH-5, 3H of BzpipH-3, H-5), 1.45 (9H, s, C(CH3)3); 19F nmr (CDCl3) δ −62.7; m/z 619 [M+H]+.
