Synthesis
Methyl 6-hydroxynicotinate (6.0 g, 39.22 mmol) and phenylboronic acid (5.74 g, 47.06 mmol) were added copper(II) acetate monohydrate (11.76 g, 58.82 mmol), pyridine (6.32 mL, 78.43 mmol), and molecular sieves (4, 6.0 g) in dichloromethane (100 mL). The reaction mixture was stirred at ambient temperature for 12 h and then filtered. After standard post-extraction treatment the crude product was obtained and purified by silica gel column chromatography (100-200 mesh, eluent chloroform solution containing 1-2% methanol) to afford methyl 6-oxo-1-phenyl-1,6-dihydro-pyridine-3-carboxylate as a brown solid (5.0 g, 56% yield). The product has a melting point of 100-105°C. 1H NMR (400 MHz, CDCl3) δ 3.86 (s, 3H), 6.63 (d, J = 9.5 Hz, 1H), 7.36-7.55 (m, 5H), 7.91 (dd, J = 2.5, 9.9 Hz, 1H), 8.23 (d, J = 2.5 Hz, 1H); IR (KBr ) ν 3058, 2924, 2854, 1721, 1675, 1540, 1446, 1313, 1271, 1103 cm-1; MS 230 (M + 1).
References
[1] Patent: US2008/319026, 2008, A1. Location in patent: Page/Page column 22
[2] Patent: WO2012/122165, 2012, A2. Location in patent: Page/Page column 63
