Potassium Hydroxide → 2-benzyl-5-(4-benzyloxyphenyl)-2H-pyrazole-3-carboxylic acid

HRID 322851Notes

Reaction equation

HRID 322851 reaction equation
[CH2:1]([N:8]1[C:12]([C:13]([O:15]CC)=[O:14])=[CH:11][C:10]([C:18]2[CH:23]=[CH:22][C:21]([O:24][CH2:25][C:26]3[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=3)=[CH:20][CH:19]=2)=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH-].[K+]>CO>[CH2:1]([N:8]1[C:12]([C:13]([OH:15])=[O:14])=[CH:11][C:10]([C:18]2[CH:23]=[CH:22][C:21]([O:24][CH2:25][C:26]3[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=3)=[CH:20][CH:19]=2)=[N:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 22010441ethyl 2-benzyl-5-(4-benzyloxyphenyl)-2H-pyrazole-3-carboxylate

Product 1

HCID 220102122-benzyl-5-(4-benzyloxyphenyl)-2H-pyrazole-3-carboxylic acidYield 49.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of ethyl 2-benzyl-5-(4-benzyloxyphenyl)-2H-pyrazole-3-carboxylate (1.2 g) in methanol (125 mL) is treated with 10% aqueous potassium hydroxide solution (10 mL, w/v) and the mixture is heated to reflux for 2 hours. The reaction mixture is evaporated in vacuo, stirred with 1N hydrochloric acid (50 mL) and extracted with ethyl acetate (100 mL). The organic phase is dried over magnesium sulphate, evaporated in vacuo, and the residue crystallised from a mixture of ethyl acetate and cyclohexane to give 2-benzyl-5-(4-benzyloxyphenyl)-2H-pyrazole-3-carboxylic acid (0.55 g), m.p. 207-208° C. [Elemental analysis:- C,75.2; H,5.20; N,7.30%. Calculated:- C,75.0; H,5.20; N,7.30%].

Workup

  1. temperaturethe mixture is heated
  2. temperatureto reflux for 2 hours
  3. customThe reaction mixture is evaporated in vacuo
  4. extractionextracted with ethyl acetate (100 mL)
  5. dry with materialThe organic phase is dried over magnesium sulphate
  6. customevaporated in vacuo
  7. customthe residue crystallised from a mixture of ethyl acetate and cyclohexane

Sources & evidence

ORD record
ord-6060e8fcfb694f68ace6ac4e8e87c9da
Source dataset
uspto-grants-2001_04
Patent number
US06211234B1

Reaction notes

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