Tert-Butyl nitrite → 5-bromo-1H-indazole

HRID 2216250

Reaction equation

HRID 2216250 reaction equation
[N:1](OC(C)(C)C)=O.[CH3:8][C:9]1[CH:14]=[C:13]([Br:15])[CH:12]=[CH:11][C:10]=1[NH:16]C(C)=O>C1(C)C=CC=CC=1>[Br:15][C:13]1[CH:14]=[C:9]2[C:10](=[CH:11][CH:12]=1)[NH:16][N:1]=[CH:8]2

Participants

4

Reactant 2

HCID 10906Tert-Butyl nitriteHCID 222277N-(4-Bromo-2-methylphenyl)acetamide

Product 1

HCID 7619295-bromo-1H-indazoleYield 38.8%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
65 °C

Procedure

tert-Butyl nitrite (8.34 g, 0.081 mol) was added dropwise, over 30 minutes, to a suspension of 4-bromo-2-methylacetanilide (12.3 g) in toluene (300 ml) at 65° C. and the mixture was stirred at 65° C. for 45 minutes and then at 90° C. for 3 hours. The mixture was cooled to room temperature and the solvent was removed in vacuo. The residue was purified by flash column chromatography on silica gel eluting with 2:1 diethyl ether:hexane to give 5-bromoindazole (4.12 g), as a sand-coloured solid.

Workup

  1. waitat 90° C. for 3 hours
  2. temperatureThe mixture was cooled to room temperature
  3. customthe solvent was removed in vacuo
  4. customThe residue was purified by flash column chromatography on silica gel eluting with 2:1 diethyl ether

Sources & evidence

ORD record
ord-2fda8f6d92014b63bcaf20807c91bf77
Source dataset
uspto-grants-2006_09
Patent number
US07112553B1

Linked notes

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