To a solution of tert-butyl 4-(bromomethyl)-5-(1-isopropyl-1H-pyrazol-5-yl)-3,6-dihydropyridine-1(2H)-carboxylate (18 mg, 0.05 mmol) and 5-hydroxy-2-methoxyisonicotinaldehyde (10 mg, 0.06 mmol) in DMF (1 mL) was added K2CO3 (14 mg, 0.1 mmol). After stirred at room temperature for 1 h, it was diluted with water and EtOAc, organic layer was separated, and the aqueous layer was extracted with EtOAc, organic layer was combined, washed with brine, dried and concentrated to give crude product, which was purified by column (Hexanes/EtOAc=2:1) to give tert-butyl 4-(((4-formyl-6-methoxypyridin-3-yl)oxy)methyl)-3-(1-isopropyl-1H-pyrazol-5-yl)-5,6-dihydropyridine-1(2H)-carboxylate (7.2 mg). 1H NMR (400 MHz, CDCl3) (ppm) 10.39 (s, 1H), 7.79 (s, 1H), 7.56 (d, J=1.6 Hz, 1H), 7.05 (s, 1H), 6.11 (d, J=1.6 Hz, 1H), 4.40 (s, 2H), 4.38 (m, 1H), 4.01 (s, 2H), 3.88 (s, 3H), 3.66 (bs, 2H), 2.46 (bs, 2H), 1.48 (s, 9H), 1.43 (d, 6.4 Hz, 6H). MS (ESI) m/z 457.3 [M+H]+.
