Highly efficient and green approach for the synthesis of spirooxindole derivatives in the presence of novel Bronsted acidic ionic liquids incorporated in UiO-66 nanocages

摘要

An efficient and green approach is reported for the rapid synthesis of spirocyclic 2-oxindole using triethylenediamine or imidazole Bronsted acidic ionic liquids supported in Zr metal-organic framework (TEDA/IMIZ-BAIL@UiO-66) as a novel, superior and retrievable heterogeneous catalyst under ultrasonic irradiation. Heterocyclic compounds including pyrido[2,3-d:6,5-d ']dipyrimidines and indeno[2 ',1 ':5,6]pyrido[2,3-d]pyrimidines were obtained by the one-pot condensation reaction of 6-amino-1,3-dimethyluracil, isatins and cyclic 1,3-diketone (barbituric acid or 1,3-indanedione). The reusability of the catalyst, low catalyst loading, short reaction times, excellent yields, simple work-up, and use of sonochemical procedure as a mild process and an alternative energy source are some of the advantages of this method. Furthermore, the novel heterogeneous nanocomposite was fully characterized using various techniques.