1429870-16-5

1375301-90-8

5-Bromo-3-methylpyridine-2-carboxylic acid 1-dimethylaminomethyl-(E)-imide (2.5 g, 9.25 mmol) was used as starting material and dissolved in tetrahydrofuran (THF, 20 mL). A solution of potassium tert-butanolate (KOtBu, 1.565 g, 13.05 mmol) in THF (30 mL) was added dropwise under stirring. The reaction mixture was heated to reflux, maintained for 3 h and then cooled to room temperature. The pH of the reaction mixture was adjusted to 7 using concentrated hydrochloric acid (HCl). subsequently, the reaction mixture was concentrated to give a brown solid. This solid was washed with water (10 mL) and collected by filtration to afford the target product 3-bromo-1,7-naphthyridin-8-(7H)-one (2 g, 8 mmol). The product was analyzed by high performance liquid chromatography (HPLC) with a retention time (RtH9) of 0.56 min; electrospray ionization mass spectrometry (ESIMS) showed [M + H]+ peaks of 224.8 and 226.8 (containing 1 bromine atom); and the chemical shifts of nuclear magnetic resonance hydrogen spectra (1H-NMR, 400 MHz, DMSO-d6) were δ11.9 (s, 1H), 8.85 (s, 1H), 8.50 (s, 1H), 7.43 (d, 1H), 6.67 (d, 1H).