Synthesis of Furan Derivatives. LIX. Synthesis of 5-Substituted-2-(2-furyl)-1, 3, 4-oxadiazoles from 1-Furoyl-2-arylidenehydrazine with Lead Tetraacetate

Hypervalent iodine(III) mediated synthesis of novel unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles as antibacterial and antifungal agents

“…Pyrazole nucleus has pronounced pharmacological applications as anti-anxiety [14], antidiabetic [15], antimicrobial [16e18], herbicidal [19,20], antiinflammatory drugs [21] and antibacterial [22e24]. Besides the dehydration of diacylhydrazines, oxidative cyclization of aldehyde N-acylhydrazones is the most known method to prepare unsymmetrically 2,5-disubstituted 1,3,4-oxadiazoles, and several reagents have been reported to in the literature which include oxidation with ceric ammonium nitrate [25], chloramine T [26], lead tetraacetate [27,28], potassium permanganate under microwaves conditions [29], ferric chloride [30], bromine/sodium acetate [31], or yellow mercuric oxide/iodine [32]. In recent years, hypervalent iodine reagents have been successfully proven their usefulness as agents for oxidative cyclization of aldehyde N-acylhydrazones to synthesize 2,5-disubstituted 1,3,4-oxadiazoles [33e38].…”