In this study, the synthesis and thermal properties of two novel maleonitriles bearing 8-membered heterocyclic derivatives is described first time. New maleonitriles, benzo-(1,2-bis-methylthio)maleonitrile
and [Benzo-15-crown-5]-(4,5-bis-methylthio)maleonitrile have been prepared by the reaction of different alkyl halides such as 1,2-bis(brommethyl)benzene and 4,5-bis-(brommethyl)[benzo-15-crown-5] with
dithiomaleonitrile disodium salt. Both compounds are characterized by IR, Mass, NMR spectroscopy as well as elemental analysis.