2-Aminopyridine → 1-{2-Methylimidazo[1,2-a]pyridin-3-yl}ethan-1-one

関与物質

反応手順

1,1′-Azobis(cyclohexanecarbonitrile) (catalytic amount) was added to a solution of pentane-2,4-dione (1.00 g, 9.99 mmol) and N-bromosuccinimide (1.96 g, 10.99 mmol) in CHCl3 (20 mL). The reaction mixture was stirred for 1 hour, filtered and the filtrate was concentrated under reduced pressure. The residue was re-dissolved in a 1:1 mixture of THF/Et2O (20 mL), then pyridin-2-amine (723 mg, 7.68 mmol) was added and the reaction mixture was refluxed overnight. After cooling the solvent was removed under reduced pressure and the residue was purified by column chromatography, eluents EtOAc, then EtOAc-MeOH (96:4), to afford the title compound (475 mg 35% yield). 1H NMR (DMSO-d6) δ (ppm): 9.59 (dt, J=6.8, 1.4 Hz, 1H), 7.68 (dt, J=8.8, 1.2 Hz, 1H), 7.56 (ddd, J=8.8, 6.8, 1.4 Hz, 1H), 7.17 (td, J=6.8, 1.4 Hz, 1H), 2.72 (s, 3H), 2.58 (s, 3H). MS (m/z): 174.20 (calc) 175.1 (MH+) (found).

情報源と証拠