Abstract: UV and ¹H NMR of twelve pairs of α-halocinnamamides substituted by aromatic ring are reported. A structure-activity relationship study of a series of(Z) and(E)-N-alkyl-α-halocinnamamides showed that geometrical isomers act differently in the anticonvulsant activty; generally, (Z) derivatives are several times more potent than (E) isomers in the anticonvulsant activity. Their configurations were assigned by their UV γmax and ¹H chemical shifts of protons on the amide group and olefinic bond. The configuration was confirmed by the X-ray diffraction results of one pair of these geometric isomers.

Key words: α-Halocinnamamides, UV, ¹H NMR, configuration