Synthesis and reactions of some 1,2,4-oxadiazole derivatives for biological evaluation

3-Aryl-l,2,4-oxadiazole-5-thiol [I] reacted with maleic acid and some of its derivatives to give 2-[3-aryl-l,2, 4-oxadiazole-5-yl-thio] succinic acid derivatives [II] and [III]. Compound [la] reacted with benzoquinone to give [IV]. 5-Amino-3-phenyl-l,2,4-oxadiazole [V] reacted with certain acid chlorides to give 5-acylamino derivatives [VI]. Compounds [VIII] were prepared by the reaction of compounds [VII] with some amines. Compound [VHIf] condensed with several aromatic aldehydes to give 5-[p-cinnamoyl-anilino]-3-phenyl-l,2,4-oxadiazole [IX]