Sodium Hydroxide → 4,5,6,7-Tetrahydro-1H-indazole-3-carboxylic acid

HRID 2182386Notes

Reaction equation

HRID 2182386 reaction equation
C([O:3][C:4]([C:6]1[C:14]2[CH2:13][CH2:12][CH2:11][CH2:10][C:9]=2[NH:8][N:7]=1)=[O:5])C.[OH-].[Na+]>CO>[NH:8]1[C:9]2[CH2:10][CH2:11][CH2:12][CH2:13][C:14]=2[C:6]([C:4]([OH:5])=[O:3])=[N:7]1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 6624328ethyl 4,5,6,7-tetrahydro-1H-indazole-3-carboxylate

Product 1

HCID 6488524,5,6,7-Tetrahydro-1H-indazole-3-carboxylic acidYield 81.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid ethyl ester [0.606 g, Reference Example 18(a)] in methanol (50 ml) was treated with sodium hydroxide (0.500 g). The mixture was refluxed for 16 hours, then cooled and then evaporated. The residual white solid was treated with hydrochloric acid (30 ml, 2N) and the resulting solution was extracted three times with ethyl acetate (50 ml). The combined organic extracts were dried over sodium sulfate and then evaporated to yield 4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid (0.424 g) as a white solid. LC-MS (METHOD B): RT=2.44 minutes; 167 (M+H)+. (b) 5-Isopropyl-1H-pyrazole-3-carboxylic acid

Workup

  1. temperatureThe mixture was refluxed for 16 hours
  2. temperaturecooled
  3. customevaporated
  4. additionThe residual white solid was treated with hydrochloric acid (30 ml, 2N)
  5. extractionthe resulting solution was extracted three times with ethyl acetate (50 ml)
  6. dry with materialThe combined organic extracts were dried over sodium sulfate
  7. customevaporated

Sources & evidence

ORD record
ord-c077f266db1d498da2afc885b9036e05
Source dataset
uspto-grants-2005_05
Patent number
US06897208B2

Reaction notes

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