Synthesis and biological evaluation of new Mannich and Schiff bases containing 1,2,4-triazole and 1,3,4-oxadiazole nucleus

摘要

5-(Pyridine-3-yl)-1,3,4-oxadiazole-2-thiole 2, obtaining starting from nicotinic acid hydrazide were converted to the corresponding Mannich bases (3a-c) by the reaction with several heterocyclic amines in the presence of formaldehyde. 1,2,4-Triazole-3-thiole, (4) prepared from 1,3,4-oxadiazole-2-thiole (2) was converted to the corresponding Mannich bases (5a-e) by several steps. The synthesis of Schiff bases (6a-d) was performed from the reaction of the corresponding triazol-3-thioles with various aromatic aldehydes. The treatment of Schiff bases containing 1,2,4-triazoles 6c and 6d with morpholine or thiomorpholine generated the corresponding Mannich bases 7a, b and 8a, b. The synthesized compounds were screened for their antimicrobial, antilipase, and antiurease activities. Some of them were found to possess good-moderate antimicrobial, antiurease, and/or antilipase activity.