Water → 1-Methyl-4-nitro-1H-indazole

HRID 1443199

Reaction equation

HRID 1443199 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-448ff966a4e34c64a3d0687be6454d6e
Source dataset
uspto-grants-2010_02
Patent number
US07659297B2

Linked notes

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