Reaction Steps
To a suspension of 8-(3-chlorophenyl)-1,6-naphthyridin-5-one (128 mg, 0.5 moles) and potassium carbonate (83 mg, 0.6 moles) in 10 ml DMF was added dropwise iodoethane (0.06 ml, 0.75 moles) under an atmosphere of nitrogen. The reaction mixture was stirred overnight at 21° C. The mixture was poured into 50 ml water and after stirring for one hour a white precipitate was collected and dried. Crystallization from ether/hexanes gave 117 mg (82% yield) of the desired 6-ethyl-8-(3-chlorophenyl)-1,6-naphthyridin-5-one as a white solid. Characteristic analytical data are as follows: mp 127°-128° C.; TLC 1:4 EtOAc/Hex; 1H NMR (CDCl3, 300 MHz) δ1.42 (t, 3H, J= 7.2), 4.11 (q, 2H, J=7.2), 7.35-7.60 (m, 6H), 8.76 (dd, 1H, J=8.0, 1.9), 8.93 (dd, 1H, J=4.5, 1.8); 13C NMR (75 MHz, CDCl3) δ161.54, 154.13, 151.62, 137.15, 136.60, 134.29, 134.16, 129.96, 129.53, 128.24, 127.70, 121.95, 119.63, 108.46, 44.62, 14.67; IR (KBr) vmax 3439, 1647, 1622, 1591, 1564, 1552, 1483, 1458, 1439, 1417, 1375, 1298, 1176, 1167, 1099, 794, 729, 711, 696, 603 cm-1 ; mass spectrum (EI), m/e 284. Anal. (C16H13ClN2O .1/8 H2O) Calcd.: C, 66.96; H, 4.57; N, 9.76. Found: C, 66.82; H, 4.55; N, 9.61.
