Microwave–assisted Synthesis of Chalcones, Flavanones and 2- pyrazolines: Theoretical and Experimental Study

Condensation of 2-acetyl-1-naphthol and 1-acetyl-2-naphthol with benzaldehydes under microwave irradiation gave chalcones or flavanones depending on the type of ketone. Also, 2-pyrazolines were synthesized by the condensation of chalcones with phenyl hydrazine under microwave irradiation in presence of dry acetic acid as a cyclizing agent. The results obtained indicated that, unlike classical heating, microwave irradiation resulted in higher yields, shorter reaction times and cleaner reactions. The structures of the synthesized compounds were elucidated using various spectroscopic methods. Theoretical studies explained the behaviour and reactivity observed for 1-acetyl-2-naphthol with benzaldehydes considering geometries, and electron densities of the formed flavanones.