Regioselective N(2)-H-functionalization of thiosemicarbazones of aromatic and heteroaromatic aldehydes with acrylonitrile

<p>Regioselective N(2)-H-cyanoethylation of thiosemicarbazones of aromatic and heteroaromatic aldehydes with acrylonitrile proceeds under mild conditions (14% KOH, acetone/H₂O, 35 °C, 6–21 h) to afford 1-(2-сyanoethyl)-2-[(<i>E</i>)-aryl(heteroaryl)methylidene]-1-hydrazinecarbothioamides in up to 74% yields. The synthesized thioamides are promising precursors of novel families of functionalized thiosemicarbazones as exemplified by hydrolysis of their cyano group to the corresponding amido function (46.5–60% yields).</p