Synthesis of Azoaryl Pyrazole, 5-one derivatives and their antibacterial activities

Abstract

The azoaryl pyrazoles and azoaryl pyrazole-5-one derivatives have been known as effective and being used as drug for many diseases, such as, antipyretic, antineuralgic, antitrichanella, antianthelmintic, antituber- culostatic, antidiabetics, and other nervous system affecting activities. The chemistry of pyrazole compounds including their preparations, reactions, properties, together with a review of their most important biological activities were dealt with in chapter one. Twelve final compounds were prepared in this work, together with their corresponding intermediates, within three steps. The first step was a one in which diazonium ion was formed from six primary aromatic amines. In the second step a coupling reaction has occurred between the diazonium ions with two active methylene compounds, acetylacetone and ethylacetoacetate in the presence of sodium acetate. The prepared intermediate diazoaryl diketo compounds include azoaryl pyrazole and azoaryl pyrazole-5-one derivatives. The third step was the enclosure of the ring in the above intermediate compounds by means of condensation reaction with the hydrazine derivative, isonizid (INH), in the presence of acetic acid to give the final compounds. The reaction course was followed with Thin Layer Chromatography (TLC). The identity of products was determined through UV., IR., 1HNMR and MS. The retrosynthetic analysis of the compounds was discussed in chapter three together with suitable mechanism of each different reactions. The spectral data were interpretated and discussed in the same chapter. The prepared compounds were found to possess good anti gram positive bacterial activity when tested against four micro-organisms : staphylococcus aureus, streptococcus pyogen, Eschrichia coli and proteus.