Methanesulfonic Acid → methyl 1H-indazole-3-carboxylate

HRID 846595Notes

Reaction equation

HRID 846595 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]([C:10]([OH:12])=[O:11])=[N:2]1.[CH3:13]S(O)(=O)=O>CO>[CH3:13][O:11][C:10]([C:3]1[C:4]2[C:9](=[CH:8][CH:7]=[CH:6][CH:5]=2)[NH:1][N:2]=1)=[O:12]

Participants

4

Reactant 2

HCID 6395Methanesulfonic AcidHCID 78250Indazole-3-carboxylic acid

Product 1

HCID 657476methyl 1H-indazole-3-carboxylateYield 60%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A stirred mixture of indazole-3-carboxylic acid (5.00 g, 0.0309 mole), methanesulfonic acid (1 ml), and methanol (100 ml) was heated at reflux temperature for 5 hours and then concentrated to a volume of 30 ml and treated with excess saturated aqueous sodium bicarbonate solution. Water was added to give a volume of 200 ml and the suspended solid was collected by filtration. The wet solid was dissolved in methylene chloride (200 ml), and the solution separated from a small amount of water and some insoluble material. The methylene chloride solution was dried (magnesium sulfate) and concentrated to yield 3.25 g (60%) of indazole-3-carboxylic acid methyl ester.

Workup

  1. temperaturewas heated
  2. temperatureat reflux temperature for 5 hours
  3. concentrationconcentrated to a volume of 30 ml
  4. additiontreated with excess saturated aqueous sodium bicarbonate solution
  5. additionWater was added
  6. customto give a volume of 200 ml
  7. filtrationthe suspended solid was collected by filtration
  8. dissolutionThe wet solid was dissolved in methylene chloride (200 ml)
  9. customthe solution separated from a small amount of water
  10. dry with materialThe methylene chloride solution was dried (magnesium sulfate)
  11. concentrationconcentrated

Sources & evidence

ORD record
ord-661518725ba049ac9e739ea4a737d14b
Source dataset
uspto-grants-1992_08
Patent number
US05137895

Reaction notes

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