Acetic Anhydride → 1-(5-Bromo-3-methyl-1H-indazol-1-yl)ethan-1-one

HRID 1097004Notes

Reaction equation

HRID 1097004 reaction equation
C(O[C:5](=[O:7])[CH3:6])(=O)C.[Br:8][C:9]1[CH:15]=[CH:14][C:12]([NH2:13])=[C:11]([CH2:16][CH3:17])[CH:10]=1.CC([O-])=O.[K+].[N:23](OCCC(C)C)=O.C1OCCOCCOCCOCCOCCOC1>C(Cl)(Cl)Cl>[C:5]([N:13]1[C:12]2[C:11](=[CH:10][C:9]([Br:8])=[CH:15][CH:14]=2)[C:16]([CH3:17])=[N:23]1)(=[O:7])[CH3:6]

Participants

7

Reactant 5

HCID 7918Acetic AnhydrideHCID 8053Isoamyl NitriteHCID 2855718-Crown-6HCID 517044Potassium AcetateHCID 28012834-Bromo-2-ethylaniline

Product 1

HCID 591273821-(5-Bromo-3-methyl-1H-indazol-1-yl)ethan-1-one

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

Acetic anhydride (4.73 ml) was added to the mixture of 4-bromo-2-ethylaniline (5.0 g) and KOAc (2.94 g) in CHCl3 (70 ml) and stirred for 30 min at reflux. Then isoamyl nitrite (6.65 ml) and 18-crown-6-ether (660 mg) was added to the reaction mixture and stirred for 12 h at reflux. The reaction mixture was diluted with CHCl3, washed with water, and dried over sodium sulfate. After filtration and concentration, the residue was purified by silica gel chromatography (hexane/ethyl acetate), and crystallized from mixed solvent of hexane and CHCl3 to give the title compound as a yellow solid.

Workup

  1. temperatureat reflux
  2. stirringstirred for 12 h
  3. temperatureat reflux
  4. washwashed with water
  5. dry with materialdried over sodium sulfate
  6. filtrationAfter filtration and concentration
  7. customthe residue was purified by silica gel chromatography (hexane/ethyl acetate)
  8. customcrystallized
  9. additionfrom mixed solvent of hexane and CHCl3

Sources & evidence

ORD record
ord-6123bf7ae6b2433687da28a27e672974
Source dataset
uspto-grants-2012_03
Patent number
US08138197B2

Reaction notes

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