反应详情

To a mixture of 110a (2.38 g, 7.00 mmol), 5-cyclopropyl-1H-pyrazol-3-amine (905 mg, 7.35 mmol), in 1,4-dioxane (40 mL) in a 100 mL single-neck round-bottomed flask was added cesium carbonate (6.84 g, 21.0 mmol). The mixture was purged with nitrogen for 30 min. Tris(dibenzylideneacetone)dipalladium(0) (641 mg, 0.700 mmol) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (688 mg, 1.19 mmol) were then added. The flask was connected to a nitrogen-purged condenser and the mixture was refluxed for 6 h under nitrogen. The mixture was cooled to room temperature and filtered. The filter cake was suspended in ethyl acetate (30 mL) and water (10 mL) and filtered through Celite®. The layers were separated. The combined organic layers were dried with anhydrous magnesium sulfate. The drying agent was removed by filtration. The filtrate was concentrated under reduced pressure. The residue was purified on silica eluted with a gradient 0 to 50% ethyl acetate in heptane to afford 6-chloro-4-(5-cyclopropyl-1H-pyrazol-3-ylamino)-2-((2-(trimethylsilyl)ethoxy)methyl)pyridazin-3(2H)-one (111a) (1.58 g, 59%).

1. customThe mixture was purged with nitrogen for 30 min
2. custompurged condenser
3. temperaturethe mixture was refluxed for 6 h under nitrogen
4. filtrationfiltered
5. filtrationwater (10 mL) and filtered through Celite®
6. customThe layers were separated
7. dry with materialThe combined organic layers were dried with anhydrous magnesium sulfate
8. customThe drying agent was removed by filtration
9. concentrationThe filtrate was concentrated under reduced pressure
10. customThe residue was purified on silica
11. washeluted with a gradient 0 to 50% ethyl acetate in heptane