Reusable ZnCr₂O₄ Nano Catalyzed One Pot Three-Component Cycloaddition Reaction for Synthesis of Azetidine Derivatives under Ultrasound Irradiation

A versatile and effectual, three-component one pot (2π + 2π) cycloaddition reaction to the synthesis of substituted azetidines in excellent yields is described. The isonicotinic acid hydrazide (1) as starting materials. Design preparation N-(7-R)-2-oxa-8-azabicyclo[4.2.0]octan-8-yl)isonicotinamide derivatives (4a-h) was carried out by condensation isoniazid with aromatic aldehyde (2a-h), ZnCr2O4 nano catalyzed one-pot Schiff base pyran (3) under ultrasonic irradiation. Moreover, Prepared nanoparticles were easily recovered corresponding solvent reused for next without significant loss their catalytic activity. confirmed XRD, EDX, TEM, HRTEM, TGA-DTA all characterized 1H NMR, 13C FT-IR, mass elemental analysis.