Sodium Hydroxide → 1H-Indazol-5-ol

HRID 2068092Notes

Reaction equation

HRID 2068092 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][N:7]=[CH:6]2.B(Br)(Br)Br.[OH-].[Na+]>C(Cl)Cl>[OH:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][N:7]=[CH:6]2

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 25134Boron tribromideHCID 133468605-Methoxy-1H-indazole

Product 1

HCID 1014381H-Indazol-5-olYield 713.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

5-Methoxyindazole (1.7 g, 11.5 mmol), (Tetrahedron, 1994, 50, 3529), was dissolved in methylene chloride (35 ml) and cooled in an ice/water bath. Boron tribromide (57.4 ml of a 1M solution in methylene chloride, 57.4 mmol) was added over 10 minutes and then the mixture allowed to warm to ambient temperature. The mixture was stirred for 2 hours and then re-cooled in an ice/water bath. 2N Sodium hydroxide was slowly added until pH8. The precipitated solid was filtered off and dried under vacuum at 60° C. overnight. The residue was purified by column chromatography eluting with methylene chloride/methanol (95/5) to give 5-hydroxyindazole (11.0 g, 65%) as a brown solid.

Workup

  1. temperaturecooled in an ice/water bath
  2. temperaturere-cooled in an ice/water bath
  3. filtrationThe precipitated solid was filtered off
  4. customdried under vacuum at 60° C. overnight
  5. customThe residue was purified by column chromatography
  6. washeluting with methylene chloride/methanol (95/5)

Sources & evidence

ORD record
ord-5141d7eff13644c8a975e32e70da4bc5
Source dataset
uspto-grants-2012_10
Patent number
US08293902B2

Reaction notes

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