One More Stable Enol:  2,2-Bis[(trifluoromethyl)thio]ethenol. Synthesis and Reactivity1

The efficient synthesis of 2,2-bis[(trifluoromethyl)thio]acetaldehyde by acidic hydrolysis of 1-(N,N-diethylamino)-2,2-bis[(trifluoromethyl)thio]ethene is presented. The tautomeric equilibrium for the compound obtained is strongly shifted to enol form, so with silver nitrate in water solution a corresponding silver salt is formed that reacts with ethyl bromide to ethyl 2,2-[(trifluoromethyl)thio]vinyl ether. The enol reacts with amines to form respective enamines. IR, MS, 1H, 13C, and 19F NMR data for compounds synthesized are given to support their structure elucidation.