Ultrasound-assisted synthesis of 2,4-thiazolidinedione and rhodanine derivatives catalyzed by task-specific ionic liquid: [TMG][Lac]

Abstract

Background: Synthesized arylidene derivs. of rhodanine and 2,4-thiazolidiendione have potent pharmacol. activities, and these are also key substrates for the prepn. of clin. used antidiabetics. Findings: Some 1,1,3,3-tetramethylguanidine-based task-specific ionic liqs. (TSILs) 1a-1e were prepd. and employed to the catalyzed solvent-free Knoevenagel condensation of 2,4-thiazolidinedione 3a and rhodanine 3b with a variety of aldehydes. Conclusions: Best results were obtained with 1,1,3,3-tetramethylguanidine lactate ([TMG][Lac]) 1c. The TSIL used can be easily recovered and recycled, yielding products 4-5 in excellent yields under ultrasonic environment without the formation of any side products or toxic waste. [on SciFinder(R)]