Green synthesis of benzimidazole derivatives under ultrasound irradiation using Cu-Schiff base complexes embedded over MCM-41 as efficient and reusable catalysts

Abstract

We have synthesized two recoverable catalysts by covalently attaching complexes such as Cu-complex-phen and Cu-complex-bipy on MCM-41 through a greener synthetic route. FT-IR, EDX, SEM and TEM microscopy, XRD analysis, N₂ adsorption and desorption, ICP-OES and TGA were used to characterize the heterogeneous catalysts. The catalytic functioning of Cu-complex-phen-MCM-41 (C₁) and Cu-complex-bipy-MCM-41 (C₂) were shown yield up to 95% for the synthesis of benzimidazole derivatives in ethanol/methanol solvent under ultrasonic irradiation within 90 min. The catalyst was easily recovered and reused up to three times without significant loss of its activity.

Graphical Abstract

Keywords:

• Schiff base
• MCM-41
• copper catalyst
• benzimidazole
• ultrasonic irradiation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The authors are grateful for the financial support from the University Grants Commission (UGC-BSR) F.30-319/2016 (BSR) New Delhi, India. The first author acknowledges to University Grants Commission-Rajiv Gandhi National Fellowship (UGC-RGNF) RGNF-2015-17-SC-TAM-21024 research grant for their financial support.