Synthetic Route of 42831-50-5, The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.42831-50-5, Name is 5-Methylisoxazole-4-carboxylic acid, molecular formula is C5H5NO3. In a Patent，once mentioned of 42831-50-5
This invention describes a process for the preparation of N-(4-trifluoromethyl)-5-methylisoxazole-4-carboxamide commonly known as leflunomide comprising : (a) reacting ethylaceto acetate, triethylorthoformate, and acetic anhydride with simultaneous distillation to form ethyl ethoxymethyleneacetoacetic ester; (b) reacting the ethyl ethoxymethyleneacetoacetic ester with aqueous hydroxylamine without using any external base and without any distillation to form ethyl-5-methylisoxazole-4-carboxylate; (c) reacting the ethyl-5-methylisoxazole-4-carboxylate with strong acid to form -5-methylisoxazole-4-carboxylic acid; (d) 5-methylisoxazole-4-carboxylic acid is reacted with thionyl chloride in presence of N, N-Dimethylformamide and equimolar of 4-trifluoromethylaniline without any external base to obtain highly pure Leflunomide.
We’ll also look at important developments in the pharmaceutical industry because understanding organic chemistry is important in understanding health, medicine, the role of 42831-50-5, and how the biochemistry of the body works.Synthetic Route of 42831-50-5
Reference：
Isoxazole – Wikipedia,
Isoxazole | C3H3NO – PubChem