反应详情

Ethyl 6-chloro-3-oxo-2,3-dihydro-1H-pyrazolo[4,3-c]pyridine-1-carboxylate (Intermediate 1B; 582 mg, 2.41 mmol), potassium carbonate (666 mg, 4.82 mmol), and benzyl bromide (0.345 mL, 2.9 mmol) were stirred in DMF (10 mL) at room temperature for 16 h. Water was added and the products extracted into EtOAc (×2). The combined organic extracts were washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo. Purification of the residue by flash chromatography (6-50% EtOAc-hexanes) gave ethyl 2-benzyl-6-chloro-3-oxo-2,3-dihydro-1H-pyrazolo[4,3-c]pyridine-1-carboxylate. MS ESI calc'd. for C16H14ClN3O3 [M+1]+ 332. found 332. Ethyl 3-(benzyloxy)-6-chloro-1H-pyrazdo[4,3-c]pyridine-1-carboxylate was also obtained. MS ESI calc'd. for C16H14ClN3O3 [M+1]+ 332. found 332.

1. extractionthe products extracted into EtOAc (×2)
2. washThe combined organic extracts were washed with brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customPurification of the residue by flash chromatography (6-50% EtOAc-hexanes)