Facile one-pot, domino reaction to synthesize (Z)-2-imino-5-(1-alkyl-2-oxoindolin-3-ylidene)thiazolidin-4-one derivatives and its DFT study for the E/Z confirmation structure

In this publication, we reported an eco-friendly procedure for the efficient synthesis of 2-imino-5-(1-alkyl-2-oxoindolin-3-ylidene) thiazolidin-4-one derivatives with a stereospecific coupling reaction between 2-imino-thiazolidin-4-one (pseudothiohydantoin) and cyano-substituted oxindole derivatives. Thus, a variety of new thiazolidin-oxindole derivatives with potential medicinal applications have been synthesized with an effective and economical method, focusing on sustainable chemistry. The final products have been obtained in excellent yields together with high purity after washing with water and ethanol. This publication is the first easy protocol to be reported for the rapid condensation of pseudothiohydantoin with substituted isatins. In addition, the stereospecificity, which led to the formation of the Z- isomer of the products is validated using computational calculations.

Automated summary

In this study, an eco-friendly procedure was developed for the efficient synthesis of 2-imino-5-(1-alkyl-2-oxoindolin-3-ylidene) thiazolidin-4-one derivatives using a stereospecific coupling reaction. The method allowed for the synthesis of various new thiazolidin-oxindole derivatives with potential medicinal applications in a cost-effective manner, emphasizing sustainable chemistry. The products obtained exhibited high yields and purity after washing with water and ethanol. This study presents a simple and rapid protocol for the condensation of pseudothiohydantoin with substituted isatins, and the computational calculations validated the stereospecificity of the Z-isomer formation.