(E)-2-Сyano-5-phenylpent-2-en-4-ynoic acid esters and N-substituted amides were synthesized by the Knoevenagel condensation of 3-phenylpropiolaldehyde with the corresponding cyanoacetates or cyanoacetamides in the presence of basic alumina used as a catalyst. The IR and Raman spectra of the resulting compounds show strong absorption bands in the range of 1565–1580 cm–1 which are attributed to the vibrations of the C=C bond in the enyl moiety.