Abstract
1) α,β-Unsaturated α-nitroesters react with n-butylamine to give 4-substituted isoxazole-3,5-carboxylic butylamides. This is a new synthesis of isoxazole derivatives. 2) The mechanistic features of the above reaction have been explained. 3) The mild alkaline hydrolysis of the above butylamides gave 4-substituted isoxazole-3,5-dicarboxylic acids.