Methyl 5-(2,2-Dimethoxyethylcarbamoyl)-3-(benzyloxy)-1,4-dihydro-1-(2,2-dimethoxyethyl)-4-oxopyridine-2-carboxylate (imp-2)
1H NMR (400 MHz, CDCl3) δ 10.1 (t, J = 5.2 Hz, 1H), 8.4 (s, 1H), 7.3–7.4 (m, 5H), 5.2 (s, 2H), 4.5(t, J = 5.2 Hz, 1H), 4.4 (t, J = 4.4 Hz, 1H), 4.0 (d, J = 4.4hz, 2H), 3.7 (s, 3H), 3.6 (t, J = 6.0 Hz, 2H), 3.4 (s, 6H), 3.3 (s, 6H) ;
13C NMR (400 MHz, CDCl3) δ 173.2, 164.2, 162.1, 148.2, 144.4, 136.7, 134.8, 128.5, 128.3, 128.1, 119.3, 102.7, 102.4, 74.3, 56.8, 55.6, 53.9, 53.1, 40.8;
IR (KBr, cm–1): 3201, 3045, 2949, 2835, 1734, 1662, 1610, 1548;
ESI-MS m/z 479.26.