1,3-Dichloroacetone → 6-chloro-2-(chloromethyl)imidazo[1,2-b]pyridazine

Participants

Reaction Steps

1,3-Dichloroacetone (21.4 g, 168.0 mmol) was added to a solution of 6-chloropyridazin-3-amine (10 g, 77.2 mmol) in acetonitrile (200 ml). The mixture was heated at reflux for 14 h (the reaction was monitored by TLC). The volatiles were removed under reduced pressure and the reaction mixture was diluted with water. The pH was adjusted to ˜7.5 with sodium bicarbonate solution and then extracted with EtOAc. The combined organics were dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by flash column chromatography using 14% ethyl acetate in n-hexane and silica gel (230-400 mesh) to afford 6-chloro-2-(chloromethyl) imidazo[1,2-b]pyridazine (6.0 g, 64.1%) as white solid. 1H NMR: 200 MHz, CDCl3: δ 8.0 (s, 1H), 7.9 (d, 1H), 7.1 (d, 1H), 4.75 (s, 2H). MS: [M+H]+: m/z=202.8.

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