Application 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
A process for preparing 5-methylisoxazole-4-carboxylic-(4?-trifluoromethyl)-anilide comprising: (a) reacting ethylacetoacetate, triethylorthoformate, and acetic anhydride at a temperature of from about 75 C. to about 150 C., to form ethyl ethoxymethyleneacetoacetic ester; (b) combining the ethyl ethoxymethyleneacetoacetic ester with sodium acetate or a salt of trifluoroacetic acid in the presence of hydroxylamine sulfate at a temperature of from about ?20 C. to 10 C., to form ethyl-5-methylisoxazole-4-carboxylate; (c) reacting the ethyl-5-methylisoxazole-4-carboxylate with a strong acid to form 5-methylisoxazole-4-carboxylic acid; (d) reacting the crystallized 5-methylisoxazole-4-carboxylic acid with thionyl chloride to form 5-methylisoxazole-4-carbonyl chloride; and (e) reacting the 5-methylisoxazole-4-carbonyl chloride with trifluoromethyl aniline and an amine base at a temperature of from about 0 C. to about 50 C. to form 5-methylisoxazole-4-carboxylic-(4?-trifluoromethyl)-anilide. The process of the invention is especially advantageous for preparing 5-methylisoxazole-4-carboxylic-(4?-trifluoromethyl)-anilide, since the process: (1) eliminates or reduces the formation of the by-product 2-cyanoacetoacetic-1-(4?-trifluoromethyl)-anilide (CATA), generally as low as 0.0006%; (2) eliminates or reduces the formation of isomeric impurity ethyl-3-methyisoxazole-4-carboxylate and its corresponding acid as low as 0.1%, (3) produces a high quality of 5-methylisoxazole-4-carboxylic-(4?-trifluoromethyl)-anilide generally having 99.8-100% HPLC potency; and (4) does not require distillation of the isoxazole ester.
A reaction mechanism is the microscopic path by which reactants are transformed into products. Each step is an elementary reaction. In my other articles, you can also check out more blogs about 42831-50-5
Reference：
Isoxazole – Wikipedia,
Isoxazole | C3H3NO – PubChem