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

HRID 2064640Notes

Reaction equation

HRID 2064640 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)+.

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-b50ccbe39e3a45fdb4929b6ff99e8427
Source dataset
uspto-grants-2012_10
Patent number
US08288425B2

Reaction notes

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