Non-covalent immobilized sultone based protic ionic liquids on nano silica sulfuric acid as novel heterogeneous catalysts for the efficient synthesis of tetrazolopyrimidines

In this research work, a novel strategy for the heterogenization of sultone based acidic ionic liquids via their non-covalent immobilization on nano silica sulfuric acid is reported and the catalytic ability of the prepared heterogeneous catalysts for the synthesis of tetrazolopyrimidines derivatives is investigated. The physicochemical properties of the prepared catalysts were studied using thermal and spectroscopic techniques such as H-1 and C-13 NMR, FTIR, SEM, TEM, TGA, EDX and BET. In the following, three-component reaction of aromatic aldehydes, active methylene compounds and 5-aminotetrazole to achieve tetrazolopyrimidine products in the presence of the introduced nano silica sulfuric acid supported acidic ionic liquids as new organic-inorganic nanohybrid catalysts was performed. The obtained results showed that the supported protic ionic liquids have better catalytic activity than their non-supported forms. Moreover, the recoverability, reusability and thermal stability of the acidic ionic liquids were also significantly improved by immobilization on nano silica sulfuric acid.

Automated summary

In this research, a novel method for the immobilization of sultone based acidic ionic liquids on nano silica sulfuric acid was developed. The prepared heterogeneous catalysts showed excellent catalytic ability for the synthesis of tetrazolopyrimidines derivatives. The physicochemical properties of the catalysts were investigated, and it was found that the supported acidic ionic liquids exhibited better catalytic activity compared to their non-supported forms.