Abstract
In order to synthesize 1-substituted amino-3, 5, 5-trimethylpyrazolines, diacetonalcohol was employed as the starting material, from which mesityloxide was prepared by the treatment with a catalytic amount of iodine, followed by the cyclization with hydrazine. The resulting 3, 5, 5-trimethylpyrazoline was converted to 1-chloroacetyl-3, 5, 5-trimethylpyrazoline by the reaction with chloroacetylchloride, followed by the reaction with a variety of amine. In this process, the reaction of mesityloxide with hydrazone was deduced to proceed probably through the intermediate of the corresponding hydrazone. Moreover, 1-β-carboethoxyethyl-3, 5, 5-trimethylpyrazoline was obtained by the reaction of 3, 5, 5-trimethylpyrazoline with ethyl acrylate.
