Synthesis of chloro pyrazolone derivatives and their biological activities

3-Methyl-5-chloro-1-phenylpyrazol and its derivatives were prepared by the reaction with 3methyl -1-phenylpyrazol-5-one, phosphorous oxytrichloride and N-N dimethyl aniline respectively using catalyst. These compounds were further treated with alcohols and sodium hydroxide to form ether linkage. Ethyl acetoacetate reacted with phenylhydrazine at reflux temprature to give 3-methyl-1phenylpyrazol-5-one crude and recrystlized from diluted ethanol to give pure 3-methyl-1-phenylpyrazol5-one. Different pyrazolone derivatives were prepared by using different phenylhydrazine derivatives. These derivatives converted in to chloro and ethereal derivatives. The structure of the compounds was also elucidated. The synthesized compounds were found to have significant effect against the tested microorganisms.