Water → 1-Methyl-4-nitro-1H-indazole

HRID 1869383Notes

Reaction equation

HRID 1869383 reaction equation
[N+:1]([C:4]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:5]=1[CH:6]=[N:7][NH:8]2)([O-:3])=[O:2].CI.[C:15](=O)([O-])[O-].[Cs+].[Cs+].O>CN(C=O)C>[CH3:15][N:8]1[C:9]2[C:5](=[C:4]([N+:1]([O-:3])=[O:2])[CH:12]=[CH:11][CH:10]=2)[CH:6]=[N:7]1

Participants

6

Reactant 4

HCID 962WaterHCID 6328Methyl iodideHCID 10796Cesium carbonateHCID 180574-Nitroindazole

Product 1

HCID 2802131-Methyl-4-nitro-1H-indazoleYield 35.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

6.5 g of 4-nitroindazole (Chem. Ber. (1904), 37, 2583), 1.9 ml of methyl iodide and 14.4 g of cesium carbonate in 110 ml of DMF are stirred for 2 hours at 0° C. and then for 12 hours at room temperature. It is added to water and extracted with ethyl acetate. The organic phase is washed with water and brine, dried (Na2SO4) and concentrated by evaporation. The residue is recrystallized from ethyl acetate/hexane. 2.49 g of 1-methyl-4-nitroindazole is obtained. The latter is hydrogenated in 70 ml of THF with 420 mg of palladium on activated carbon under normal pressure with hydrogen. The batch is filtered through diatomaceous earth and completely concentrated by evaporation. 2.1 g of the title compound is obtained.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe organic phase is washed with water and brine
  3. dry with materialdried (Na2SO4)
  4. concentrationconcentrated by evaporation
  5. customThe residue is recrystallized from ethyl acetate/hexane

Sources & evidence

ORD record
ord-d009cd32ee0f4f1bb4118c608cce24c4
Source dataset
uspto-grants-2009_12
Patent number
US07638515B2

Reaction notes

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