(2-Bromoethoxy)-tert-butyldimethylsilane → 1-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-5-methyl-6-nitro-1H-indazole

HRID 539634Notes

Reaction equation

HRID 539634 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][C:10]=1[N+:11]([O-:13])=[O:12])[NH:7][N:6]=[CH:5]2.C[Si](C)(C)N[Si](C)(C)C.[Li].Br[CH2:25][CH2:26][O:27][Si:28]([C:31]([CH3:34])([CH3:33])[CH3:32])([CH3:30])[CH3:29]>CN(C=O)C>[C:31]([Si:28]([CH3:30])([CH3:29])[O:27][CH2:26][CH2:25][N:7]1[C:8]2[C:4](=[CH:3][C:2]([CH3:1])=[C:10]([N+:11]([O-:13])=[O:12])[CH:9]=2)[CH:5]=[N:6]1)([CH3:34])([CH3:33])[CH3:32]

Participants

5

Reactant 3

HCID 3608067(2-Bromoethoxy)-tert-butyldimethylsilaneHCID 126378375-methyl-6-nitro-1H-indazoleHCID 57426343Lithium bis(trimethylsilyl)amide

Product 1

HCID 582002841-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-5-methyl-6-nitro-1H-indazoleYield 50.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

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.

Workup

  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)

Sources & evidence

ORD record
ord-933131830ed74175b9f95171e75526c7
Source dataset
uspto-grants-2014_10
Patent number
US08871760B2

Reaction notes

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