THE 1,2-THIADIAZOLE ROUTE TO NEW VINYLOGUE TETRATHIAFULVALENES

Cleavage of 1,4-dithiafulvene-substituted 1,2,3-thiadiazoles with base and dimerisation of the resulting alkyne-1-thiolate gives new tetrath iafulvalene-type vinylogue extended pi-donors in a one pot reaction. T he solvent-/base-system used (acetonitrile/NaH) was optimised for the synthesis of 1,3-dithiole-2-thiones via this route. Efficient synthesi s of the important 4-formyl-1,3-dithiol-2-thione and its coupling to 2 ,6(7)-bisformyltetrathiafulvalene is presented. Preparation of a numbe r of new 1,4-dithiafulvenes are reported.