Novel pyridazine derivatives: Synthesis and antimicrobial activity evaluation.

A general method for the preparation of new hydrazones is reported. The 1-[4-(2-methoxybenzyl)-6-aryl pyridazin-3(2H)-ylidene] hydrazines or their tautomeric structures (1(a-d)) were condensed with different aldehydes, dialdehydes, ketones, alpha-dicarbonyl compounds and simple carbohydrates to afford the hydrazones and dihydrazones (2(a-d)), (3(a-d)), (4(a-d)), (5(a-d)), (6(d)), (7(c)), (8(a-d)), (9(a-d)), (10(a-d)), (11(a-d)), (12(a,c,d)), (13(a-d)), (14(a-d)), (15(a-d)), (16(a-d)) and (17(a-d)). The structures of all synthesized compounds were confirmed from microanalytical and spectral data. Some of the products were screened for their antimicrobial activity against Staphylococcus aureus and Streptococcus faecalis, Escherichia coli and Pseudomonas aeruginosa. The hydrazone derivative 15(d) (1-[4-(2-methoxybenzyl)-6-methylphenyl pyridazin-3(2H)-ylidene]-2-(2-carboxydiphenyl methyl) hydrazine) showed the highest biological activity.