6-Amino-3-chloropyridazine → 3-Amino-4-bromo-6-chloropyridazine

Participants

Reaction Steps

To a suspension of 6-chloropyridazin-3-amine (30 g, 232 mmol), NaHCO3 (39 g, 464 mmol) and methanol (576 mL) was added Br2 (11.9 mL, 232 mmol) drop wise over 30 minutes at room temperature. The mixture was stirred for 16 h then filtered and concentrated in vacuo. The residue was purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=3:1) to give 4-bromo-6-chloropyridazin-3-amine (31.5 g, 65%) as a light orange solid. LC-MS: [M+H]+, 207.9, 209.9, tR=1.189 min.

Provenance & Evidence