Coupling of Paba Diazonium Chloride with Active Methylenes And Their Microbial Evaluations

Abstract

Diazotization of P-amino benzoic acid was carried out in presence of sodium nitrite and hydrochloric acid Followed by coupling reaction with activated methylene group in presence of sodium acetate and ethanol to yield the corresponding substituted aryl azo (I-V). The coupling adducts were reacted with hydrazine hydrate under reflux in ethanol in presence of tri ethyl amine to yield the pyrazolone derivatives (VIVIII). Also acetylation of the coupling adducts with acetic anhydride gave only (IX) while the rest of compounds did not react .The compounds (I-IX) were tested against microorganisms such as gram negative bacteria(E-coli Neisseria and Salmonella) in comparable with different antibiotics, for example Ampicillin. Keywords: dyes, PABA, diazoamino coupling, active methylene