Synthesis of new tricyclic spiro-naphthalene-1,3,4-oxadiazoles via 1,3-dipolar cycloadditon reactions

This thesis presents a study on the synthesis of a new series of naphthoquinone derivatives via 1,3-dipolar cycloaddition reactions. Naphthoquinone skeletal structure is a synthetically important and adaptable class of chemical compounds, shows a wide range of biological and pharmacological activities. In this study, 2,3-disubstituted-1,4-naphthoquinones were reacted with various hydrazonyl chlorides in ethanol in the presence of triethylamine at boiling temperature to give twelve novel 2,3-bis(phenylthiol)-spiro[naphthalene-1,2'-[1,3,4]oxidiazole]-4-ones. The products precipitated in the reaction medium were purified by washing with cold ethanol. The yields obtained in the synthesis of the products were moderate to good. The synthesized compounds were characterized using various analytical techniques such as NMR spectroscopy, IR spectroscopy and mass spectrometry.