反应详情

温度

-10 °C

A 2 M solution of n-butyl magnesium chloride in THF (22.4 mL, 44.8 mmol) was added to toluene (160 mL) under nitrogen and cooled to −10° C. To this was added a 1.6 M solution of n-butyl lithium in hexane (57 mL, 91 mmol) and after 1 h, the RM was cooled to −30° C. To the RM was then added a solution of 5-bromo-6-fluoro-1-methyl-1H-indazole ((v) 19.0 g, 83 mmol) in THF (160 mL) and the reaction was warmed up to −10° C. After 1 h, DMF (8.23 mL, 106 mmol) was added and the RM was stirred at −10° C. for another 1 h. The reaction was quenched using 2 N HCl and was allowed to warm up to room temperature. After 30 min, the RM was basified with saturated aqueous NaHCO3 solution and then extracted with EtOAc. The organic phase was washed with brine, dried over Na2SO4 and evaporated under vacuo. The residue was triturated with Et2O. The precipitate formed was filtered off to give a beige solid identified as the desired aldehyde (tR 3.61 min (conditions 1), NMR in DMSO-d6: 10.16 (s, 1H); 8.36 (d, 1H); 8.30 (s, 1H); 7.70 (d, 1H); 4.03 (s, 3H)).

1. temperaturethe RM was cooled to −30° C
2. temperaturethe reaction was warmed up to −10° C
3. waitAfter 1 h
4. customThe reaction was quenched
5. temperatureto warm up to room temperature
6. waitAfter 30 min
7. extractionextracted with EtOAc
8. washThe organic phase was washed with brine
9. dry with materialdried over Na2SO4
10. customevaporated under vacuo
11. customThe residue was triturated with Et2O
12. customThe precipitate formed
13. filtrationwas filtered off
14. customto give a beige solid