Chalcone

Different phenacyl bromides were reacted with 2-amino pyridine to give 2-aryl imidazo[1,2-a] pyridines, which on subsequent reaction with Vilsmeier-Haack reagent gave 2-aryl imidazo[1,2-a] pyridine carbaldehydes (4a-4b). Claisen-Schmidt condensation of 4a and 4b with different substituted acetophenones afforded chalcones (5a-5f). The reaction of chalcones with phenyl hydrazine gave six new derivatives of pyrazolyl imidazo[1,2-a]pyridines (6a-6f ) in good yields. The synthesized compounds were characterised on the basis of physical and spectral data. The compounds were evaluated for anti-inflammatory and anti-bacterial activities. The compounds 6a, 6b, and 6c exhibited potent anti-inflammatory activity and results are comparable with standard drug, ibuprofen. None of the compounds showed any significant antimicrobial activity even at a concentration of 1000 µg/ml against Gram +ve and Gram –ve organisms.

Chalcones are a category of compounds consisting of two aryl rings linked by an α,β-unsaturated ketone moiety. The synthesized compounds CEA and CMA were evaluated for antimicrobial activity by disc diffusion method. The antibacterial and antifungal activity was evaluated against Moraxella, Enterobacter, Pseudomonas aeruginosa (bacterial strains), Candida albicans, A.niger and Trichophyton (fungal strains) using Erythromycin (for bacteria) and Ciprofloxacin (for fungi) as the standard drugs. The structure of synthesized compounds has been elucidated by IR, 1H, 13C NMR and elemental analysis.