反应详情

A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 1,4-dioxane (150 mL), pyrimidin-4-amine (1.7 g, 18.0 mmol), 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one (4.0 g, 18.0 mmol), and cesium carbonate (11.74 g, 36.0 mmol). After bubbling nitrogen through the suspension for 30 minutes, Xantphos (1.04 g, 1.8 mmol) and tris(dibenzylideneacetone)dipalladium(0) (823 mg, 0.9 mmol) were added. The system was subjected to three cycles of vacuum/argon flush and heated at reflux for 15 h. It was then cooled to room temperature and filtered. The solid was washed with dichloromethane (2×50 mL). The combined filtrate was concentrated and the residue was washed with acetonitrile (5 mL) to afford 263a (2.99 g, 70%) as a yellow solid. MS: [M+H]+ 238

1. customA 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser
2. customAfter bubbling nitrogen through the suspension for 30 minutes
3. customflush
4. temperatureheated
5. temperatureat reflux for 15 h
6. filtrationfiltered
7. washThe solid was washed with dichloromethane (2×50 mL)
8. concentrationThe combined filtrate was concentrated
9. washthe residue was washed with acetonitrile (5 mL)