| Abstract: | CLAISEN -Condensations with Selected Dithioesters - Synthesis of Special 3-Methylthio-acrylnitriles . A useful synthetic route to the mono- and diheteroaryl-3-methylthio-acrylnitriles 1 and 2 is demonstrated by the thioanalogous CLAISEN -condensation. In the presence of sodium hydride in tetrahydrofurane or under PTC-conditions heteroaryl dithiocarboxylic esters 3 react with CH-acidic compounds 4 or 9 to form 3-mercapto-acrylnitriles (e. g. 5 ). Methylation leads to mono- and diheteroaryl-3-methylthioacrylnitriles 1 and 10 (type 2 ). In the same manner tetrathioterephthalic ester 6 reacts with two equivalents of CH-acidic compounds yielding 8 and 11 . By means of spectroscopic methods, especially 1H- and 13C-n.m.r., the structures of the compounds obtained are confirmed. |
