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.

Graphical Abstract

Keywords:

• ZnCr₂O₄
• three-component one-pot reaction
• azetidine derivatives
• aromatic aldehydes
• ultrasound irradiation

Acknowledgements

Authors are grateful to Management of Doshi Vakil Arts and G.C.U.B. Science & Commerce College, for providing research related facilities.

Disclosure statement

The authors confirm that, this article content has no conflict of interest.

Scheme 3. Plausible reaction mechanism for of N-(7-R)-2-oxa-8-azabicyclo[4.2.0]octan-8-yl)isonicotinamide derivatives (4a-h)

Scheme 1. Model reaction for synthesis of N-(7-(2,5-dimethoxyphenyl)-2-oxa-8-azabicyclo[4.2.0]octan-8-yl)isonicotinamide derivatives (4a).