Methanol → methyl 1H-indazole-3-carboxylate

HRID 2064573Notes

Reaction equation

HRID 2064573 reaction equation
S(=O)(=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>>[NH:6]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:8]([C:15]([O:17][CH3:18])=[O:16])=[N:7]1

Participants

4

Reactant 3

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

Product 1

HCID 657476methyl 1H-indazole-3-carboxylate

Procedure

0.5 ml of concentrated sulphuric acid (95%) is added dropwise, at a temperature in the region of 20° C., to a solution of 9.13 g of 3-indazolecarboxylic acid in 100 ml of methanol. After refluxing for 20 hours, the reaction medium is concentrated under reduced pressure at a temperature in the region of 40° C. The aqueous residue obtained is extracted with dichloromethane. The organic phases are combined, washed with water until neutral, dried over magnesium sulphate and then concentrated under reduced pressure at a temperature in the region of 40° C. The yellow powder obtained is washed with ethyl ether. A white powder is obtained. The filtrate is concentrated under reduced pressure until a yellow powder is obtained. This yellow powder is washed again with ethyl ether until a white powder is obtained. The yellow filtrate is concentrated a third time under reduced pressure and the yellow powder collected is itself also washed with ethyl ether. All the fractions of white powder are combined. 7.08 g of methyl 3-indazolecarboxylate are thus obtained in the form of a white powder.

Workup

  1. temperatureAfter refluxing for 20 hours
  2. concentrationthe reaction medium is concentrated under reduced pressure at a temperature in the region of 40° C
  3. customThe aqueous residue obtained
  4. extractionis extracted with dichloromethane
  5. washwashed with water until neutral,
  6. dry with materialdried over magnesium sulphate
  7. concentrationconcentrated under reduced pressure at a temperature in the region of 40° C
  8. customThe yellow powder obtained
  9. washis washed with ethyl ether
  10. customA white powder is obtained
  11. concentrationThe filtrate is concentrated under reduced pressure until a yellow powder
  12. customis obtained
  13. washThis yellow powder is washed again with ethyl ether until a white powder
  14. customis obtained
  15. concentrationThe yellow filtrate is concentrated a third time under reduced pressure
  16. customthe yellow powder collected
  17. washalso washed with ethyl ether

Sources & evidence

ORD record
ord-53787dc0cad547ee8775bda6c6a68ded
Source dataset
uspto-grants-2012_10
Patent number
US08288425B2

Reaction notes

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