反应详情

温度

0 °C

5-Methyl-6-nitro-1H-indazole (354 mg, 2.0 mmol) was dissolved in DMF (10 ml) and the mixture was cooled to 0° C. with stirring. Lithium hexamethyldisilazane (2.2 ml of 1.0 M toluene solution) was added dropwise. The mixture was allowed to stir for five minutes, and then (2-bromoethoxy)-tert-butyldimethylsilane (0.52 ml, 2.4 mmol) was added. The mixture was stirred for 30 minutes at 0° C., then allowed to warm to room temperature with stirring for four hours. The reaction was quenched with pH2 buffer solution, and the mixture was then extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash chromatography (gradient 9:1 to 4:1 hexanes/ethyl acetate) to give 340 mg (50.7%) of 1-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-5-methyl-6-nitro-1H-indazole as a white powder.

1. stirringto stir for five minutes
2. stirringThe mixture was stirred for 30 minutes at 0° C.
3. temperatureto warm to room temperature
4. stirringwith stirring for four hours
5. customThe reaction was quenched with pH2 buffer solution
6. extractionthe mixture was then extracted with ethyl acetate
7. washThe organic layer was washed with brine
8. dry with materialdried over anhydrous sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe residue was purified by flash chromatography (gradient 9:1 to 4:1 hexanes/ethyl acetate)