Synthesis of derivatives of new heterocyclic system 5,7-dioxo(4h,6h)-1,3-dithiolo[4,5-d]pyrimidine on the basis of barbituric acid
The 5-phenyliodonium betaine of barbituric acid reacts with sodium diethyldithiocarbamate to form 5-(diethylaminothiocarbonylthio)barbituric acid, which is cyclized in concentrated H2SO4 solution to form the cation of 5,7-dioxo(4H,6H)-1,3-dithiolo[4,5-d]pyrimidine, isolated in the form of the perchlorate and the chloride. These salts are split by sodium sulflde or selenide, forming 5-[diethylaminothio (seleno)carbonylthio]-4-thiobarbituric acids, which are cyclized by the action of concentrated HCl in an organic solvent to form 5,7-dioxo(4H,6H)-1,3-dithiolo[4,5-d]pyrimidinethione (selenone)-2. The thione and the selenone, as NH acids, form salts; alkylation of the tetrabutylammonium salt affords N(4)-alkyl and N,N′-dialkyl derivatives. The compounds that were obtained have been characterized by IR and PMR spectra.