Abstract
In this study, silica sodium carbonate (SSC) as an eco-friendly solid recyclable Brønsted base and highly efficient catalyst has been successfully applied to green and promoted selective synthesis of benzylpyrazolocoumarins in aqueous medium. Using this solid Brønsted catalyst has some advantages in the synthesis of benzylpyrazolocoumarins including obtaining excellent yields of products, short reaction times, green and safety protocol, easy to handle, and capability of catalyst to recycle. By this achievement some interesting potential biological active compounds were obtained via a green procedure.
Methods: A green and highly efficient protocol for the catalytic synthesis of benzylpyrazolocoumarins by the use of SSC as an eco-friendly and recyclable Brønsted base is introduced.
Results: Some potential biologically active benzylpyrazolocoumarins were efficiently synthesized via a green Domino reaction. To examine generality of the reaction, a wide range of both electron-rich and electron-poor aryl aldehydes were applied. The efficiency of catalyst on the reaction progress with other acidic and basic catalysts were studied and compared with each other. Also, the capability of the catalyst to reuse was evaluated that the results showed SSC can be reused upto five times without remarkable miss of activity.
Conclusion: The SSC showed that could successfully catalyze alternative Knoevenagel condensations and Michael addition reactions. Furthermore, by this achievement some important potential biologically active products were efficiently synthesized in a green procedure.
Keywords: Benzylpyrazolocoumarin, silica sodium carbonate, green catalyst, heterogeneous solid base, green procedure, aqueous medium.
Graphical Abstract
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