[OH-].[Na+].[NH2:3][C:4]1[N:8]([C:9]2[CH:14]=[CH:13][C:12]([C:15]([F:18])([F:17])[F:16])=[CH:11][N:10]=2)[N:7]=[CH:6][C:5]=1[C:19]([O:21]CC)=[O:20]>C(O)C>[NH2:3][C:4]1[N:8]([C:9]2[CH:14]=[CH:13][C:12]([C:15]([F:18])([F:17])[F:16])=[CH:11][N:10]=2)[N:7]=[CH:6][C:5]=1[C:19]([OH:21])=[O:20]10 ml of 45% strength aqueous sodium hydroxide solution are added to 18 g (0.06 mole) of 5-amino-1-(5-trifluoromethyl-pyrid-2-yl)-4-ethoxycarbonyl-pyrazole in 100 ml of 50% strength aqueous ethanol solution and the mixture is stirred at 80° C. for 4 hours. For working up, the solvent is removed in vacuo, the residue is taken up in 50 ml of water and the mixture is stirred into a solution of 20 ml of concentrated hydrochloric acid and 50 ml of water. The precipitate is filtered off with suction, washed with a little dilute hydrochloric acid and dried at 50° C. in vacuo. 15.4 g (94.4% of theory) of 5-amino-1-(5-trifluoromethyl-pyrid-2-yl)-pyrazole-4-carboxylic acid of melting point 196° C. (decomposition) are obtained.
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