SYNTHESIS OF NOVEL PYRAZOLE, COUMARIN AND PYRIDAZINE DERIVATIVES EVALUATED AS POTENTIAL ANTIMICROBIAL AND ANTIFUNGAL AGENTS

The reaction of cyanoacetylhydrazine with ω-bromoacetophenone gave the N’-[2-bromo-1-phenylethylidene]-2-isocyanoacetohydrazide (3). The latter compound underwent ready cyclization when treated with potassium cyanide to give the 1-(isocyanoacetyl)-3-phenyl-1H-pyrazol-5-amine (6). Compound 6 underwent a series of heterocyclization to give either coumarin, pyridazine, 1,2,4-triazine or thiophene derivatives. The antimicrobial and antifungal activities of the newly synthesized products were measured, using two Gram-negative (Escherichia coli and Pseudomonas aeruginosa), two Gram-positive bacteria (Bacillus subtilis and Bacillus cereus) and the antifungal activity using Candida albicans