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

Participants

Reaction Steps

2,6-Dichloroimidazo[1,2-b]pyridazine (1.6 g, 8.5 mmol), [1,3-bis(diphenylphosphino)propane]nickel (II) dichloride (catalytic amount) and dehydrated tetrahydrofuran (20 ml) were introduced into a 100-ml three-necked flask under a nitrogen stream and stirred under ice-cooling, and a solution of propylmagnesium chloride in tetrahydrofuran (2 M, 6.4 ml, 12.8 mmol) was added dropwise thereto at 10° C. or less. After dropping, the mixture was stirred for 1 hour at the same temperature, for 1 hour at room temperature and for 2 hours at 50 to 60° C. After the reaction was completed, the reaction solution was left and cooled, and water (50 ml) was added thereto, and the mixture was stirred and extracted with ethyl acetate (20 ml×2). The organic layers were combined, washed with water, dried over magnesium sulfate and concentrated, and the residues were purified by silica gel column chromatography (hexane:ethyl acetate=2:1) to give the title compound as orange crystals (containing a small amount of impurities). The yield was 0.8 g (48.2%).

Provenance & Evidence