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

Abstract

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