反应详情

A mixture of 3-benzyloxy-6-chloro-pyridazine (4 g), thiourea (2.8 g) and ethyl methyl ketone (75 mL) was prepared and refluxed overnight. Excess ethyl methyl ketone was evaporated and the resulting residue was extracted with 2M sodium hydroxide (25 mL). The sodium hydroxide solution was then washed with ethyl acetate (2×30 mL). The aqueous layer was collected and sufficient concentrated hydrochloric acid was added to bring the pH to 5. The resulting solution was extracted with ethyl acetate (2×30 mL). The ethyl acetate extract was collected, dried, filtered, and the filtrate was evaporated to afford the title compound (15%, 605 mg); mp, 155-157° C.

1. customwas prepared
2. temperaturerefluxed overnight
3. customExcess ethyl methyl ketone was evaporated
4. extractionthe resulting residue was extracted with 2M sodium hydroxide (25 mL)
5. washThe sodium hydroxide solution was then washed with ethyl acetate (2×30 mL)
6. customThe aqueous layer was collected
7. additionsufficient concentrated hydrochloric acid was added
8. extractionThe resulting solution was extracted with ethyl acetate (2×30 mL)
9. extractionThe ethyl acetate extract
10. customwas collected
11. customdried
12. filtrationfiltered
13. customthe filtrate was evaporated