| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preparing a 1-substituted pyrazole-4-carboxylic acid simply and in a high yield which is expected to have its usefulness as an intermediate of drugs for chronic rheumatism, allergic rhinitis, asthma, cardinovascular diseases and the like. SOLUTION: The method for preparing the 1-substituted pyrazole-4-carboxylic acid comprises reacting an alkyl ester of 4-pyrazolecarboxylic acid with an organic halogen compound in an alcohol solvent in the presence of an alkyl metal hydroxide (I) to obtain an alkyl ester of a 1-substituted pyrazole-4-carboxylic acid, then adding water to the system to perform the hydrolysis of the ester, and further adding an acid to the system to make the pH of the system 1.0-4.0. COPYRIGHT: (C)2005,JPO&NCIPI
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