Synthesis of pyrazolyl phosphonates by using amine-functionalized metakaolin

Abstract

The simple extrusion method used to combine metakaolin (MK) with aminoethyl-3-aminopropyltriethoxysilane (AEAPTES) to create composite (MK/AEAPTES) is described in this article. Owing to amine group inherent on MK, it exhibited a basic nature. The novel basic catalyst is used for the synthesis of pyrazolyl phosphonates by Michael-addition reaction. Significant product yields, environmental friendliness, rapid reaction durations, broad range of substrate compatibility, and lack of hazardous solvent requirement make these reactions remarkable. Furthermore, there is no appreciable decrease in activity subsequently five recycles of the catalyst and catalyst separation using a straightforward filtration technique without any extraction. The synthesized derivatives were characterized by ¹H, ¹³C NMR, and ³¹P NMR & FT-IR analysis. Synthesized composite is analyzed by FT-IR, XRD, and SEM–EDX, investigation is compared with MK. The recycled catalyst is also checked by FT-IR, XRD, and SEM–EDX analysis.