Methanol → 4-chloro-1-(difluoromethyl)-1H-pyrazole-3-carboxylic acid

HRID 1626108Notes

Reaction equation

HRID 1626108 reaction equation
C[O:2][C:3]([C:5]1[C:9]([Cl:10])=[CH:8][N:7]([CH:11]([F:13])[F:12])[N:6]=1)=[O:4].[OH-].[Li+].O.CO>O1CCCC1>[Cl:10][C:9]1[C:5]([C:3]([OH:4])=[O:2])=[N:6][N:7]([CH:11]([F:12])[F:13])[CH:8]=1

Participants

6

Reactant 4

HCID 887MethanolHCID 962WaterHCID 3939Lithium HydroxideHCID 574758834-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester

Product 1

HCID 574758564-chloro-1-(difluoromethyl)-1H-pyrazole-3-carboxylic acidYield 93.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester (540 mg, 2.6 mmol) in tetrahydrofuran (18 ml) was treated at 23° C. with a solution of lithium hydroxide (135 mg, 5.6 mmol) in a 1:1-mixture of water and methanol (12 ml). After 1 hour the reaction was complete, and the solvents were evaporated at reduced pressure. The residue was partitioned between 2 M aqueous hydrochloric acid and ethyl acetate. The organic layer was dried, evaporated, the residue was triturated with pentane and the solid was dried to give the title compound (477 mg) as a white solid. MS (ISP): m/z=195.0 [M−H]−.

Workup

  1. customthe solvents were evaporated at reduced pressure
  2. customThe residue was partitioned between 2 M aqueous hydrochloric acid and ethyl acetate
  3. customThe organic layer was dried
  4. customevaporated
  5. customthe residue was triturated with pentane
  6. customthe solid was dried

Sources & evidence

ORD record
ord-6fd7a6a6e29c4e0d902c882fff193ad1
Source dataset
uspto-grants-2014_07
Patent number
US08785436B2

Reaction notes

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