Reaction Steps
A 25 ml RB flask with a stirring bar was charged with 4-[5-methoxy-3-(2-thienyl)-1,6-naphthyridin-2-yl]benzaldehyde (1-5) (62 mg, 0.18 mmol), followed by 2-(3-piperidin-4-yl-1H-1,2,4-triazol-5-yl)pyridine dihydrochloride (1-6) (82 mg, 0.36 mmol), anhydrous DMF (1.0 mL), triethylamine (72 mg, 0.716 mmol), and acetic acid (107 mg, 1.79 mmol). Then sodium triacetoxyborohydride (76 mg, 0.36 mmol) was added in one portion, and the resulting pale yellow solution was stirred at 23° C. overnight. The mixture was diluted with sat. ammonium chloride solution (10 mL), extracted twice with ethyl acetate (10 mL). The crude mixture was purified by column chromatography on silica gel (0-30% methanol/dichloromethane) to give 5-methoxy-2(4-{[4-5-pyridin-2-yl-4H-1,2,4-triazol)piperidin-1-yl]methyl}phenyl)-3-(2-thienyl)-1,6-naphthyridine (1-7). 1H NMR (CDCl3, ppm) δ: 8.54 (bs, 1H), 8.51 (s,1H), 8.10 (d, J=6.0 Hz, 1H), 8.01 (d, J=7.8 Hz, 1H), 7.68 (t, J=7.7 Hz, 1H), 7.42 (d, J=8.0 Hz, 2H), 7.37 (d, J=6.9 Hz, 1H), 7.29 (d, J=8.0 Hz, 2H), 7.25 (t, J=3.4 Hz, 1H), 7.19 (d, J=5.1 Hz, 1H), 7.15 (s, 1H), 6.81 (t, J=3.6 Hz, 1H), 6.68 (d, J=3.1 Hz, 1H), 4.05 (s, 3H), 3.98 (s, 2H), 3.35 (s, 1H), 3.25 (bs, 2H), 3.02 (bs, 2H), 2.75 (bs, 2H), 2.19 (bs, 2H).
