Methanol → methyl 1H-indazole-3-carboxylate

HRID 1743361Notes

Reaction equation

HRID 1743361 reaction equation
OS(O)(=O)=O.[NH:6]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:8]([C:15]([OH:17])=[O:16])=[N:7]1.[CH3:18]O>>[CH3:18][O:16][C:15]([C:8]1[C:9]2[C:14](=[CH:13][CH:12]=[CH:11][CH:10]=2)[NH:6][N:7]=1)=[O:17]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 78250Indazole-3-carboxylic acid

Product 1

HCID 657476methyl 1H-indazole-3-carboxylateYield 61%

Procedure

Concentrated H2SO4 (1 mL) was added to a solution of indazole-3-carboxylic acid (2.0 g, 12 mmol) in MeOH (40 mL). The reaction mixture was heated at reflux for 3 h, the MeOH was removed under reduced pressure and the residue was partitioned between diethyl ether (100 mL) and H2O (100 mL). Saturated sodium hydrogen carbonate solution was added (100 mL) and the diethyl ether layer was separated. The aqueous layer was further extracted with 2×200 mL of diethyl ether. The combined extracts were dried (MgSO4) and solvent removed under reduced pressure and the solid was recrystallised from cyclohexane/ethyl acetate to afford the title compound (1.29 g, 61%). Mp 158–159° C., lit 168–169° C. v.Auwers, Dereser Chem. Ber. 1919, 52, 1343.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 3 h
  3. customthe MeOH was removed under reduced pressure
  4. customthe residue was partitioned between diethyl ether (100 mL) and H2O (100 mL)
  5. additionSaturated sodium hydrogen carbonate solution was added (100 mL)
  6. customthe diethyl ether layer was separated
  7. extractionThe aqueous layer was further extracted with 2×200 mL of diethyl ether
  8. dry with materialThe combined extracts were dried (MgSO4) and solvent
  9. customremoved under reduced pressure
  10. customthe solid was recrystallised from cyclohexane/ethyl acetate

Sources & evidence

ORD record
ord-09c07be5d93d490fbc697c3e2777085e
Source dataset
uspto-grants-2006_03
Patent number
US07009056B2

Reaction notes

Loading…