Sodium Hydroxide → 7-Bromo-2-methyl-2H-indazole-3-carboxylic acid

HRID 902562Notes

Reaction equation

HRID 902562 reaction equation
C[O:2][C:3]([C:5]1[N:6]([CH3:15])[N:7]=[C:8]2[C:13]=1[CH:12]=[CH:11][CH:10]=[C:9]2[Br:14])=[O:4].[OH-].[Na+]>C(O)C>[Br:14][C:9]1[C:8]2[C:13](=[C:5]([C:3]([OH:4])=[O:2])[N:6]([CH3:15])[N:7]=2)[CH:12]=[CH:11][CH:10]=1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 58861011Methyl 7-bromo-2-methyl-2H-indazole-3-carboxylate

Product 1

HCID 210946187-Bromo-2-methyl-2H-indazole-3-carboxylic acidYield 94.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
55 °C

Procedure

A mixture of 7-bromo-2-methyl-2H-indazole-3-carboxylic acid methyl ester (35a; 0.215 g, 0.799 mmol), 8 mL of a 2 M aqueous NaOH solution, and 6 mL of ethanol was stirred at 55° C. overnight, then concentrated to remove ethanol. The remaining aqueous layer was acidified with a 10% aqueous HCl solution and extracted with three 20 mL portions of ethyl acetate. The combined organic layers were dried over Na2SO4, filtered, and concentrated to afford crude 7-bromo-2-methyl-2H-indazole-3-carboxylic acid (35e; 0.193 g; 94%) which was used without further purification.

Workup

  1. concentrationconcentrated
  2. customto remove ethanol
  3. extractionextracted with three 20 mL portions of ethyl acetate
  4. dry with materialThe combined organic layers were dried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-c6abcbab167842aeb8d8f4134623e77c
Source dataset
uspto-grants-2008_04
Patent number
US07365211B2

Reaction notes

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