反应详情

5-Bromo-2H-indazole (2 g, 9.85 mmol) was dissolved in THF (50 mL) and cooled down to −40° C. n-BuLi in n-hexane (1.6 M, 15.4 mL) was added dropwise. After 15 min stirring, DMF (1.53 mL, 19.7 mmol) was added and the RM was stirred 30 min at −40° C. before warming up to rt. After 1 h, water was added (60 mL) and the mixture was extracted 3 times with EtOAc. Combined organic layers were washed with brine and dried on Na2SO4. After evaporation of the solvent the crude was purified by flash chromatography (CombiFlash® Companion System®, with 12 g RediSep® silica gel column, n-hexane/EtOAc=100:0->50:50) to afford the title compound (tR 3.63 min (conditions 3), MH−=145).

1. additionwas added dropwise
2. stirringthe RM was stirred 30 min at −40° C.
3. waitAfter 1 h
4. extractionthe mixture was extracted 3 times with EtOAc
5. washCombined organic layers were washed with brine
6. customdried on Na2SO4
7. customAfter evaporation of the solvent the crude
8. customwas purified by flash chromatography (CombiFlash® Companion System®, with 12 g RediSep® silica gel column, n-hexane/EtOAc=100:0->50:50)