反应详情

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.

1. temperatureThe solution was cooled
2. additionpoured into a mixture
3. concentrationThe water layer was concentrated under vacuum
4. customthe 2-amino-1-propanol was removed by bulb to bulb distillation under high vacuum
5. temperatureThe residue in 50 ml of thionyl chloride was refluxed for 0.5 hours
6. customthe volatiles were removed in vacuo
7. additionTo the residue was added 150 ml of ethanol and 5 g of potassium carbonate
8. temperatureThe mixture was refluxed for 4 hours
9. customThe solvent was evaporated in vacuo
10. customthe residue was partitioned between dichloromethane and water
11. extractionThe aqueous layer was extracted with three 50 ml portions of dichloromethane
12. dry with materialThe combined organic layers were dried over magnesium sulfate
13. customthe solvent was removed in vacuo
14. additionEther was added to the residue
15. customa brown solid was removed by filtration
16. additionThe addition of hexane to the filtrate
17. temperatureon chilling
18. customgave crystals which
19. customwere recrystallized from ether-hexane