Background: In the present study, we performed according to green chemistry’s standards,
an easy and very efficient one-pot synthesis of2-thioxo-1,3-thiazolidin-4-one(rhodanine) and
thiazolidine-2,4-dione (TZD) derivatives via Knoevenagel condensation of various aldehydes with
rhodanine/ thiazolidine-2,4-dione in the presence of only 15 mole% of deep eutectic solvents (DESs)
-choline chloride/urea- propionate and microwave radiation under solvent-free conditions.
Method: Twenty compounds were synthesized under thermal and microwave conditions and the
yields of synthesized compounds were 77-90% and 81-95%, respectively. The IR spectra were obtained
on a PerkineElmer FT-IR spectrophotometer using KBr disks.1H NMR and 13C NMR of products
were registered Bruker 500 spectrometer and chemical shifts are expressed as d (ppm) with tetramethylsilane
(TMS) as an internal standard in DMSO-d6 as a solvent. The purity of synthesized
compounds was checked by chromatography and UV light (254 nm) was used for visualization.
Result: A range of rhodanine and -2, 4-thiazolidinedione derivatives were synthesized using ChCl/
urea catalyst under solvent -free conditions at 80°C. Then, the sample derivatives were synthesized
under optimum conditions.
Conclusion: The mild reaction conditions, good to excellent yields, easy workup, without the involvement
of any harmful solvents/chemicals and easily available substrates, they all facilitated in
the preparation of all synthesized compounds.