An efficient carbodiimide-mediated synthesis and DNA-binding studies of novel 2-chloro/mercapto-quinoline-fused 1,3-thiazolidinones via one-pot three-component condensation

Abstract

A new and efficient method for the preparation of 2-(2-chloroquinolin-3-yl)-3-(4-methylphenyl)-1, 3-thiazolidin-4-one derivatives has been assembled by DCC:-mediated three-component one-pot reaction of amine, aldehyde, and mercaptoacetic acid. The final compounds were obtained in quantitative yields within 50 min. The synthesized compounds were characterized by elemental analysis, FT-IR, ¹H-NMR, and mass spectral data. The selected compounds were studied for interaction with calf thymus DNA by electronic spectra, viscosity measurements as well as thermal denaturation studies. On binding to DNA, the absorption spectrum underwent bathochromic and hypochromic shifts. The binding constant (K _b) had a value of 5.3×10⁵ M⁻¹ for 2a and 5.8×10⁵ M⁻¹ for 3a. The viscosity measurements indicated that the viscosity of sonicated rod-like DNA fragments increased.

Keywords:

• quinoline
• DCC
• thiazolidinones
• one-pot synthesis
• DNA binding
• viscosity measurements
• thermal denaturation

Acknowledgements

D.S.L. thanks the Indian Institute of Science, Bangalore, and Karnataka University, Dharwad, for providing spectral data and Cochin University, Sophisticated Test & Instrumentation Center, Kochi, Kerala, for the elemental analysis facility, and we also thank Kuvempu University for awarding a research fellowship.