Synthesis and Antiradical Activity of 2-Arylidenemalonic Acid Dianilides

The most common cinnamoyl anilines are avenanthramides, which are natural antioxidants found in oats. This is a rather uncommon and not well-investigated group of antioxidants. This paper deals with 2-arylidenemalonic acid dianilides – cinnamoyl anilines which are decorated with an additional arylaminocarbonyl moiety at α-position of double bond. The DPPH scavenging activity of the title compounds is slightly lower in comparison to the corresponding cinnamoyl anilines. On the other hand, the title dianilides are more active than cinnamic acid anilides containing an additional carboxylic group in the α-position of double bond.

[3+2] Cycloadditions: Part XXXV. Selective Cycloadditions of C-(4-Chlorophenyl)-N-methyl Nitrone to Cinnamic Acid Anilides

[3+2] Cycloadditions of nitrones as three-atom components to alkenes yield isoxazolidine cycloadducts, which on chemical transformations can be converted to bioactive compounds. The [3+2] cycloadditions route thus provides conversion of simple natural products to more complex naturally occurring bioactive nitrogen heterocycles, and close analogues. As α,β-unsaturated amides abundantly occur as natural products, [3+2] cycloadditions of nitrones with simpler α,β-unsaturated amides were studied to get information about reactivity profiles. The reactions of C-(4-chlorophenyl)-N-methyl nitrone as three-atom component to cinnamic acid anilides were investigated. The 3,4-trans-4,5-trans-4- carboxanilido-2-methyl-3,5-diaryl isoxazolidines were the major cycloadducts; the diastereoisomeric 3,4-cis-4,5-trans-4-carboxanilido-2-methyl-3,5-diaryl isoxazolidines and regioisomeric 3,4-trans-4,5- trans-5-carboxanilido-2-methyl-3,4-diaryl isoxazolidines were obtained as minor cycloadducts. The cycloadducts were characterized by NMR studies and XRD analysis.