反应详情

Tert-butyldimethylsilyl chloride (6.05 g, 40.15 mmol) and imidazole (2.92 g, 42.82 mmol) were added to a stirred solution of ethyl 5-oxo-4,5-dihydro-1H-pyrazole-3-carboxylate (4.18 g, 26.76 mmol) in ACN (90 mL). The mixture was stirred at room temperature for 30 minutes, then diluted with water and extracted with AcOEt. The organic layer was separated, dried (Na2SO4), filtered and the solvents evaporated in vacuo to yield ethyl 5-{[tert-butyl(dimethyl)silyl]oxy}-1H-pyrazole-3-carboxylate (3.2 g, 44% yield) as a yellow solid, that was used in the next step without further purification.

1. extractionextracted with AcOEt
2. customThe organic layer was separated
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. customthe solvents evaporated in vacuo