Convenient procedures have been developed for the synthesis of 2-(1,3-dithiolan-2-ylidene)-malononitriles and 2-cyano-2-(1,3-dithiolan-2-ylidene) acetamides from disodium alk-1-ene-1,1-dithiolates and 1,2-dichloroalkanes, as well as from malononitrile or cyanoacetamide in a one-pot mode.
An environmentally friendly method of synthesis of 2-ylidene-1,3-dithiolanes in the system water-sodium ethene-1,1-dithiolate-haloalkane was developed. The method does not make use of toxic solvents and catalysts and provides high-purity dithiolanes.