Caesium tetrathiafulvalene-thiolates: key synthetic intermediates

Treatment of cyanoethylated tetrathiafulvalene-thiolates or cyanoethylated 1,3-dithiole-2-thione-4,5-dithiolate with one equiv. of caesium hydroxide hydrate selectively and in high yield produces the corresponding monocaesium salts, which can subsequently be alkylated.