Bromine → 3-Bromo-6-chloroimidazo(1,2-b)pyridazine

Participants

Reaction Steps

Bromine (3.8 mL, 74.19 mmol) was added dropwise to a solution of 6-chloroimidazo[1,2-b]pyridazine (Preparation 1a, 4.8 g, 31.06 mmol) in glacial acetic acid (80 mL) and the resulting mixture was stirred at ambient temperature for 20 minutes. The precipitate formed was collected by filtration, washed with diethyl ether several times and dried in vacuo. The solid obtained was partitioned between ethyl acetate and a saturated aqueous solution of potassium carbonate. The organic layer was separated and washed with a saturated aqueous solution of potassium carbonate, dried over magnesium sulphate and the solvent removed under reduced pressure. The crude was then treated with pentane, filtered and the solid obtained was dried in vacuo to yield the title compound (6.6 g, 92%) as a pale yellow solid.

Provenance & Evidence