Synthesis and Antioxidant Activity of Furan Derivatives Containing a 1,3,4-Oxadiazole Ring

Methyl 5-aminomethylfuran-2-carboxylates reacted with methylamine to give 5-aminomethylN-methylfuran-2-carboxamides, and their hydrolysis afforded the corresponding carboxylic acids. The reaction of methyl 5-aminomethylfuran-2-carboxylates with hydrazine hydrate produced hydrazides which were acylated with benzoyl or 2-furoyl chloride and then subjected to heterocyclization to obtain furan derivatives containing a 1,3,4-oxadiazole ring. The target products were also synthesized in one step by reacting 5-aminomethylfuran-2-carbohydrazides with acid chlorides in the presence of phosphoryl chloride.