Efficient Synthesis of Rhodanine-Based Amides via Passerini Reaction using Tetramethylguanidine-Functionalized Silica Nanoparticles as Reusable Catalyst

Sheida Barzegar,Robabeh Baharfar,Razieh Azimi,Mojtaba Mohseni

doi:10.5935/0103-5053.20150108

Abstract

Novel rhodanine-based amide derivatives were prepared in good yields via Passerini reaction of rhodanine-N-acetic acid with aromatic aldehydes and tert-butyl isocyanide in the presence of tetramethylguanidine immobilized on silica nanoparticles (TMG-SiO2 NPs) as a heterogeneous base catalyst. The synthesized compounds were evaluated for their antibacterial effects against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis.

Highlights

Multicomponent reactions (MCRs) are valuable synthetic tool to prepare diverse and complex molecular structures from simple building blocks and offer high efficiency and atom economy.[1]
The Passerini reaction is classified as an isocyanide multicomponent reaction (IMCR), and deals with the condensation of an isocyanide, an aldehyde and a carboxylic acid.[2,3]
Nano silica-supported tetramethylguanidine was synthesized according to reported procedure in the literature,[15] by silylation/condensation of nano silica with (3-chloro propyl)trimethoxy silane, which was reacted with tetramethylguanidine to form TMG-SiO2 NPs catalyst (Scheme 1)

Summary

Introduction

Multicomponent reactions (MCRs) are valuable synthetic tool to prepare diverse and complex molecular structures from simple building blocks and offer high efficiency and atom economy.[1]. 4-thiazolidinones are important scaffolds because of their biological properties including antitubercular,[17] anticancer,[18,19] anticonvulsant,[20] antifungal,[21] antibacterial,[21] and hypnotic activities.[22] in continuation of our investigations on the synthesis of biological compounds[23,24] and the use of heterogeneous catalysts for chemical preparation,[25,26] we disclose a Passerini reaction for the synthesis of rhodanine-based amides in good yields by the condensation of rhodanineN-acetic acid with aromatic aldehydes and tert-butyl isocyanide in the presence of tetramethylguanidinefunctionalized silica nanoparticles (TMG-SiO2 NPs) as a heterogeneous basic catalyst.

Results

Conclusion