反应详情

温度

70 °C

5-nitroindazole (15 g, 92 mmol, 1 eq), 3-fluorobenzylbromide (14.7 mL, 119.5 mmol, 1.3 eq) and potassium carbonate 25.4 g (184 mmol, 2 equiv) were suspended in 150 mL acetonitrile. The reaction mixture was stirred at 70° C. for 12 h, and then allowed to cool to rt. The resultant solid was filtered and washed with CH2Cl2, and the filtrate concentrated in vacuo. The crude mixture of regioisomeric products was purified by column chromatography (5:1 to 4:1 Hex/EtOAc), yielding 5-nitro-1-N-(3-fluorobenzyl)indazole (7.9 g, 32%) and 5-nitro-2-N-(3-fluorobenzyl)indazole (9.2 g, 37%) as yellow solids.

1. temperatureto cool to rt
2. filtrationThe resultant solid was filtered
3. washwashed with CH2Cl2
4. concentrationthe filtrate concentrated in vacuo
5. additionThe crude mixture of regioisomeric products
6. customwas purified by column chromatography (5:1 to 4:1 Hex/EtOAc)