Fremgangsmate for krystallisering av N-(4-trifluormetylfenyl)-5-metyl-isoksazol-4-karboksamid

The invention relates to a process for obtaining N-(4-trifluoromethylphenyl)-5-methyl-isoxazole-4-carboxamide in crystalline form, which is essentially free of byproducts. For this purpose, N-(4-trifluoromethylphenyl)-5-methylisoxazole-4-carboxamide is transferred into an organic solvent or into mixtures of organic solvents and water, the amount of byproduct in the solution is determined by quantitative analysis and an equimolar amount of a base is added. N-(4-Trifluoromethylphenyl)-5-methyl-isoxazole-4-carboxamide is isolated from the resulting solution by crystallization.