反应详情

According to Scheme 7, Step 1: At −78° C., BuLi (23 mmol, 9.2 mL, 2.5M) was added dropwise to a solution of acetonitrile (21.1 mmol, 0.87 g) in THF (25 mL). The resulting mixture was stirred at this temperature for 20 minutes and then ethyl 1-(4-methoxybenzyl)-1H-pyrazole-4-carboxylate (19.2 mmol, 5.00 g) in THF (25 mL) was added. The reaction mixture was stirred at −78° C. for 1 hour and then allowed to warm up to room temperature and stirred for another 1 hour. The reaction was quenched with saturated NH4Cl aqueous solution and extracted with EtOAc (50 mL×3). The combined organic phases were dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified on combi-flash EtOAc/PE (1:15 to ˜1:5) to give 3-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)-3-oxopropanenitrile (13.1 mmol, 3.33 g, 68%).

1. stirringThe reaction mixture was stirred at −78° C. for 1 hour
2. stirringstirred for another 1 hour
3. customThe reaction was quenched with saturated NH4Cl aqueous solution
4. extractionextracted with EtOAc (50 mL×3)
5. dry with materialThe combined organic phases were dried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified on combi-flash EtOAc/PE (1:15 to ˜1:5)