[Cl:1]N1C(=O)CCC1=O.[CH3:9][N:10]1[CH:19]=[CH:18][C:17]2[C:12](=[CH:13][CH:14]=[N:15][CH:16]=2)[C:11]1=[O:20]>C(#N)C>[Cl:1][C:18]1[C:17]2[C:12](=[CH:13][CH:14]=[N:15][CH:16]=2)[C:11](=[O:20])[N:10]([CH3:9])[CH:19]=1N-chlorosuccinimide (0.8 g, 6.2 mmol) was added in portions to a solution of 2-methyl-2,6-naphthyridin-1-one (1.0 g, 6.2 mmol) in acetonitrile (25 mL) which was then heated at 65° C. for 18 h. Extractive work up with ethyl acetate and purification by silica gel chromatography (PE:EA=5:1-1:1) gave the title compound of step 1 (0.6 g, 56%) as a yellow solid. 1H NMR: (CDCl3, 400 MHz) δ 9.29 (s, 1H), 8.81 (d, J=3.6 Hz, 1H), 8.21 (d, J=5.2 Hz, 1H), 7.31 (s, 1H), 3.63 (s, 3H). LCMS: 195.0 (M+H)+.
Wird geladen…