Michael Addition Reactions of Nitroalkane on Chalcones and Study of their Antioxidant and Antimicrobial Activities


The present work Involves the synthesis, characterization, Antioxidant and biological activity of a new series of Michael Addition which content a nitro group, the synthetic routes have been divided into three steps as follows:

The first part include synthesis of 4-benzyloxybenzaldehyde (67) Via williamson O-alkylation reaction between 4-hydroxy benzaldehyde (54) with benzyl bromide (45) in the Presence of  potassium carbonate anhydrous as a catalyst and Dimethylformamide as solvent under stirring condition at room temperature for 3 hours.

The second part of this work contained the synthesis of a series of chalcone Compounds by Claisen–Schmidt condensation of 4-benzyloxybenzaldehyde (67) with different substituted aromatic acetophenone, using ethanol as a solvent and NaOH as a catalyst, stirred at room temperature for 24 hours.

The third part of this work contained synthesis of Michael Addition (190a-d) through addition of nitromethane (168) to chalcone derivatives (189a-d) in Dimethylformamide and NaOH as a catalyst under stirring condition at room temperature for 2-4 hours.

The FT-IR, 1H-NMR and 13C-NMR spectra of synthesized compounds confirmed the structure of proposed structures, which provided the expected frequencies and signals. Finally, the antioxidant activity of synthesized compounds were tested as compared to standard ascorbic acid, the result showed that the synthesized compounds have antioxidant activity. All synthesized compounds were evaluated for their antibacterial activity against two types of pathogenic bacteria (Staphylococcus aureus) as Gram positive and (Escherichia coli) as Gram negative and antifungal activities against (Candida albicans). The results showed different antimicrobial activity of the synthesized compounds were effective against both types of bacteria and fungi.