1,2,4-oksadiazol halkası içeren bazı yeni azidlerin sentezi ve halka katılma tepkimeleri

In this work, in the first step, we aimed to obtain a number of 5-chloromethyl 1,2,4-oxadiazoles starting from p-substituted aromatic monoamidoximes. Then, 5-azidomethyl 3-aryl substituted 1,2,4-oxadiazoles were easily prepared from the reaction of chloromethyl 1,2,4-oxadiazoles and sodium azide in DMSO. To our best knowledge of literature survey, both a great number of chloromethyl oxadiazoles and all the azidomethyl oxadiazoles are novel heterocyclic compounds not known yet. As the major part of this work, 1,3-dipolar cycloaddition reactions of these novel 3-aryl substituted 5-azidomethyl 1,2,4-oxadiazoles with the dipolarophiles like N-phenyl maleimide, phenyl vinyl sulfone and some bicylic olefinic dipolarophiles which were easily synthesized from furan-maleic anhydride and furan-N-phenyl maleimide reactions were performed to afford bicylic and tricyclic cycloaddition products which might be expected to exhibit biological activity. These cycloadducts are the members of substituted 1,6-dihydropyrrolo-[1,2,3] triazoles, substituted-4-phenylsulfonyl-4,5-dihydro-[1,2,3] triazoles and 8,8a-hexahydro-4,8-epoxyfuro-[1,2,3] triazoles. The structures of all the cycloadducts were elucidated by means of IR, NMR (1H, 13C), MASS spectra and physical characteristics (melting points and Rf values).