TAUTOMERISM OF 2,5-DIMERCAPTO-1,3,4-THIAD IAZOLE AND SYNTHESIS OF THIADIAZOLOACRIDINES

Some 2(3H)-thione-5-alkylthio-1,3,4-thiadiazoles were prepared with a view to arylating these compounds with 9-chloroacridines. Using pyridi ne as solvent and base, this arylation led to the one-(N)3-acridinyl-5 -alkylthio-1,3,4-thiadiazoles. Molecular structures of the latter were determined either by NMR spectroscopy or by referring to X-ray crysta llography of the diethylaminoethylthio)-1,3,4-thiadiazole-2-thione. Th us, with respect to the tautomeric equilibrium of the compound investi gated, the thione group was detected either in the solid state or in s olution. In contrast, 2-acridinylthio-5-alkylthio-1,3,4-thiadiazoles w ere prepared by using the sodium salt of 2-mercapto-5-alkylthio-1,3,4- thiadiazoles as starting material.