Reactions of methylated 5-chloro-1,2,3-thiadiazolium salts with cyclohexane-1,3-diones: X-ray crystal structure analysis of the thiapentalenic products

Abstract

The N-3 methylated thiadiazolium salt 3 reacts with cyclohexane-1,3-dione and 5,5-dimethylcyclohexane-1,3-dione to give mesoionic 1,2,3-thiadiazoles (5 and 6) with short intramolecular S ⋯ O contacts, whereas the N-2 methylated thiadiazolium salt 4 furnishes oxathiole derivatives (7 and 8) with short intramolecular S ⋯ N contacts.