Bromine → 3-Bromo-1,5-naphthyridine

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 1,5-naphthyridine (C-1) (50.0 g, 384 mmol, 1.0 eq) and sodium acetate (62.9 g, 768 mmol, 2.0 eq) in acetic acid (300 mL) at 80° C., a solution of bromine (67.5 g, 422 mmol, 1.1 eq) in acetic acid (80 mL) was added dropwise while keeping the reaction temperature at 80° C. to 90° C. After stirring for 2 h at 80° C., the reaction was complete based on TLC analysis. The resulting mixture was cooled to RT and then filtered. The filtrate was concentrated in vacuo and the residue was purified by flash column chromatography on silica gel (0-30% ethyl acetate-petroether) to afford the desired product 3-bromo-1,5-naphthyridine (C-2) (36.5 g, 45% yield) as a pale yellow solid. 1H NMR (300 MHz, CDCl3-d6) δ: 8.97 (m, 2H), 8.57 (s, 1H), 8.37 (d, J=8.4 Hz, 1H), 7.65 (m, 1H); ESI-MS m/z: 208.96 [M+H]+.

Provenance & Evidence