Title of article :
Nano kaolin-SO3H as a new efficient and reusable catalyst for one-pot synthesis of 2,4,5-trisubstituted imidazoles in solvent-free conditions
Abstract :
Nano kaolin-SO3H as a new reusable and green heterogeneous catalyst was
prepared by the reaction of kaolin nanoparticles with chlorosulfonic acid. This new type
of solid acid, which contains the properties of a Lewis acid (Al3+) and a Br?nsted acid
(SO3H group), was characterized by FT-IR, XRD, SEM, TEM, XRF, EDS, and TGA. Nano
kaolin-SO3H was used as a recoverable acidic heterogeneous catalyst for one-pot synthesis of
2,4,5-trisubstituted imidazoles via three-component condensation of 1,2-diketones, various
aromatic aldehydes, and ammonium acetate. Short reaction time, simple workup, high
yields, solvent-free conditions, and environmental friendly catalysts are some advantages of
this protocol.
