Water → 1-(4-fluorophenyl)-3-methyl-1H-pyrazole-4-carboxylic acid

Reaction equation

O.[F:2][C:3]1[CH:8]=[CH:7][C:6]([N:9]2[CH:13]=[C:12]([C:14]([O:16]CC)=[O:15])[C:11]([CH3:19])=[N:10]2)=[CH:5][CH:4]=1.[OH-].[Na+]>C(O)C>[F:2][C:3]1[CH:4]=[CH:5][C:6]([N:9]2[CH:13]=[C:12]([C:14]([OH:16])=[O:15])[C:11]([CH3:19])=[N:10]2)=[CH:7][CH:8]=1

Participants

Procedure

To a mixed solvent of ethanol (40 ml) and water (40 ml) were added ethyl 1-(4-fluorophenyl)-3-methylpyrazole-4-carboxylate (8.5 g) and sodium hydroxide (1.66 g), and the mixture was stirred at a refluxing temperature for 2 h. After the reaction, ethanol was evaporated and to the residue was added dilute hydrochloric acid. The obtained solid was recrystallized from aqueous methanol solution to give the title compound, melting point: 194–195° C.