Synthesis of Thieno[2,3-d]-1,3-dithiol-2-thiones from Thieno[2,3-d]-1,2,3-thiadiazoles: Matryoshka-type autoclave for high-temperature, high-pressure thermolysis microscale reactions

Thieno[2,3-d]-1,2,3-thiadiazoles (1) react with carbon disulfide in a "Matryoshkatype" double compartment autoclave [1] to yield thieno[2,3-d]-1,3-dithiol-2-thiones (2). With BH3/Me2S the cyclic trithiocarbonate (2d) is cleaved and the product characterized after methylation as 4b. Compounds 7a and 7b are prepared via the thieno[2,3-d]-1,3-dithiolium salts (6) followed by NaBH4-reduction.