Synthesis, antituberculostatic, antifungal and antibacterial activities of 3-substituted phenyl-6-substituted phenyl-1,2,4-triazolo[4,3-b]pyridazines.

Triazole and itís derivatives are noteworthy for their physiological and biological importance. They paved the attention of medicinal chemist due to their wide range of biological activities like anti-inflammatory (1ñ5), antibacterial (6ñ8), anticonvulsant (9), antifungal (10ñ14) and anticancerous (15) etc. In view of above facts and inspired by the research going on triazole and its derivatives, particularly in relation to microbial infections, 3-substituted phenyl-6-substituted phenyl-1,2,4-triazolo[4,3b]pyridazines have been synthesized. The final compounds were synthesized according to reaction sequence outlined in Scheme 1. Friedel-Crafts acylation of appropriate hydrocarbons with succinic anhydride, in the presence of anhydrous AlCl3 yielded β-aroyl propionic acids followed by hydrazinolysis with hydrazine hydrate to get substituted pyridazinones, which reacted with phosphoryl chloride to give 3-chloro-6-substituted phenyl-pyridazines. This intermediates, after reaction with hydrazine hydrate, were converted into 3-hydrazino-6-substituted phenyl-pyridazines. They reacted with substituted aroyl chlorides to yield 3-substituted phenyl-6substituted phenyl-1,2,4-triazolo[4,3-b]pyridazines. All structures of the final compounds were confirmed by NMR, IR and mass spectral data. The compounds were evaluated for antituberculostatic, antifungal and antibacterial activities. The physicochemical data of the synthesized compounds are presented in Table 1. SHORT COMMUNICATION