Water → 2,3-Dihydro-3-methyl-6-(3-pyridinyl)imidazo[1,2-b]pyridazine

Beteiligte Stoffe

Reaktionsschritte

A 4.0 g sample of 3-chloro-6-(3-pyridinyl)pyridazine in 56 ml of 2-amino-1-propanol was heated at 140° C. for 8 hours. The solution was cooled, then poured into a mixture comprised of 200 ml of ether and 300 ml of water. The water layer was concentrated under vacuum and the 2-amino-1-propanol was removed by bulb to bulb distillation under high vacuum. The residue in 50 ml of thionyl chloride was refluxed for 0.5 hours then the volatiles were removed in vacuo. To the residue was added 150 ml of ethanol and 5 g of potassium carbonate. The mixture was refluxed for 4 hours. The solvent was evaporated in vacuo and the residue was partitioned between dichloromethane and water. The aqueous layer was extracted with three 50 ml portions of dichloromethane. The combined organic layers were dried over magnesium sulfate and the solvent was removed in vacuo. Ether was added to the residue and a brown solid was removed by filtration. The addition of hexane to the filtrate on chilling gave crystals which were recrystallized from ether-hexane to give 1.2 g of 2,3-dihydro-3-methyl-6-(3-pyridinyl)imidazo[1,2-b]pyridazine as orange crystals, mp 103.5°-105° C.

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