Thiourea is an inexpensive, efficient and mild catalyst for the synthesis of Knoevenagelcondensation of pyrozoles derivate. In the presence of 10 mol% of thiourea, pyrazole aldehyde react with active methylene compound under microwave‐assisted solvent‐free conditions at 300 W for 2‐5 min to give corresponding products in good yields.
A green and efficient methodology has been developed for the construction of 2-[(1,3-diaryl-4-pyrazolyl)methylene]malononitriles, potent antioxidant molecules, in good to excellent yields in five minutes from 1,3-diarylpyrazole-4-carbaldehydes and malononitrile using PEG-400 and water at ambient temperature under catalyst-free conditions. The PEG-400 could be reused without appreciable loss in the yield. The methodology has been extended to the synthesis of a diverse range of homo/heteroaryl-based nitriles and acrylates, reflecting its versatility.
A Mechanochemical Approach for the Construction of Carbon–Carbon Double Bonds: Efficient Syntheses of Aryl/Heteroaryl/Aliphatic Acrylates and Nitriles
carbon–carbon double bond has been developed from aromatic aldehydes and compounds with active methylene moieties in the presence of catalytic amount of solid sodiumethoxide via mechanochemical approach. This capable process provides a diverse range of homoaryl/heteroaryl/aliphatic acrylates and nitriles in good to excellent yields at short reaction period.Graphical Abstract