Hydrochloric Acid → 2-Chloro-6-propylimidazo[1,2-b]pyridazine

Beteiligte Stoffe

Reaktionsschritte

Under a nitrogen stream, 2,6-dichloroimidazo[1,2-b]pyridazine (1.00 g, 5.32 mmol), bis(triphenylphosphine)nickel(II) dichloride (0.10 g, 0.16 mmol) and zinc bromide (0.04 g, 0.16 mmol) were added to tetrahydrofuran (8.0 ml), and a solution of n-propylmagnesium bromide in tetrahydrofuran (2 M, 3.99 ml, 7.98 mmol) was added dropwise over 10 minutes to the mixture under ice-cooling. The reaction mixture was stirred for 10 minutes under ice-cooling, and warmed to room temperature and stirred for 4 hours at room temperature. Cold water (100 ml) was added to the reaction mixture which was then acidified with dilute hydrochloric acid, and extracted with ethyl acetate. The extracts were washed with dilute hydrochloric acid, a saturated saline, an aqueous saturated sodium bicarbonate solution and a saturated saline in this order. The resulting organic layer was dried over anhydrous magnesium sulfate, filtrated and concentrated. The concentrated residue was purified by silica gel column chromatography (ethyl acetate:hexane=3:7) to give the title compound as pale yellow crystals. The yield was 0.76 g (73.1%).

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