Solvent-Drop Grinding Method: Efficient Synthesis, DPPH Radical Scavenging and Anti-diabetic Activities of Chalcones, bis-chalcones, Azolines, and bis-azolines

Highly efficient one-pot solvent-free grinding method was reported for synthesis of chalcones 3a-j, 5a,b, 7 and bis-chalcones 9, 11. Cyclodehydration of bis-chalcones 9, 11 and chalcones 3 with hydrazine derivatives under solvent-free grinding method afforded bis-pyrazolines 12a,b, 13a,b and pyrazoline derivatives 14a-g, respectively. In a similar manner, grinding of bis-chalcones 9, 11 and chalcones 3 with hydroxylamine hydrochloride under the employed reaction conditions gave bis-isoxazolines 15, 16 and isoxazoline derivatives 17a-e, respectively. The antioxidant activity of the selected products was studied using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay. Also, the antidiabetic activity of the selected products against normal and alloxan induced diabetic mice was evaluated.