Hydrochloric Acid → 1-Benzyl-1H-pyrazole-4-carboxylic acid

HRID 1097871Notes

Reaction equation

HRID 1097871 reaction equation
C([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:10]=1)=[O:5])C.[Li+].[OH-].Cl>C1COCC1>[CH2:11]([N:9]1[CH:10]=[C:6]([C:4]([OH:5])=[O:3])[CH:7]=[N:8]1)[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 3939Lithium HydroxideHCID 15237993ethyl 1-benzyl-1H-pyrazole-4-carboxylate2×

Product 1

HCID 64838761-Benzyl-1H-pyrazole-4-carboxylic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
60 °C

Procedure

This known compound [CAS Reg. No. 401647-24-3] was made from 1-benzyl-1H-pyrazole-4-carboxylic acid ethyl ester by saponification: 1-benzyl-1H-pyrazole-4-carboxylic acid ethyl ester (2.35 g) was dissolved in dry THF (25 mL) and then a 1M aqueous solution of LiOH (15.31 mL) was added. The mixture was stirred at 60° C. for 2.5 hours and analyzed by TLC: starting material was still visible. Another batch of LiOH monohydrate (1.29 g) was added and the mixture was allowed to stir at room temperature for 48 hours. The mixture was poured into ice water and acidified with 2M aqueous HCl (20 mL). The aqueous phase was extracted with ethyl acetate and the organic layer was washed with brine, dried over Na2SO4 and evaporated to give the title compound as a colorless solid (1.55 g). MS (m/e, ISP neg. ion)=201.6 [(M−H+)−].

Workup

  1. stirringto stir at room temperature for 48 hours
  2. extractionThe aqueous phase was extracted with ethyl acetate
  3. washthe organic layer was washed with brine
  4. dry with materialdried over Na2SO4
  5. customevaporated

Sources & evidence

ORD record
ord-78e3afc8fefd477f966de131299da549
Source dataset
uspto-grants-2012_03
Patent number
US08143280B2

Reaction notes

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