反应详情

4,4,5,5-Tetramethyl-2-(1H-pyrazol-4-yl)-1,3,2-dioxaborolane (10 g), N,N-dimethylacetamide (100 ml), potassium carbonate (17.8 g) and t-butyl bromoacetate (9.9 ml) were mixed, and the mixture was stirred at room temperature for 4 hr. The reaction mixture was filtered through celite. Water and ethyl ether were added to the filtrate, and the mixture was partitioned in a separatory funnel. The aqueous layer was extracted with ethyl ether, and the organic layers were combined. The organic layer was washed 3 times with water and once with saturated brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure, hexane (50 ml) was added to the obtained residue and the mixture was stirred. This slurry was filtered, and the obtained solid was washed with hexane, and dried under reduced pressure to give the title compound (12.23 g, 77%).

1. filtrationThe reaction mixture was filtered through celite
2. additionWater and ethyl ether were added to the filtrate
3. customthe mixture was partitioned in a separatory funnel
4. extractionThe aqueous layer was extracted with ethyl ether
5. washThe organic layer was washed 3 times with water
6. dry with materialonce with saturated brine, dried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationThe filtrate was concentrated under reduced pressure, hexane (50 ml)
9. additionwas added to the obtained residue
10. stirringthe mixture was stirred
11. filtrationThis slurry was filtered
12. washthe obtained solid was washed with hexane
13. customdried under reduced pressure