Efficient Multi-component Synthesis of Highly Substituted Imidazoles Utilizing P2O5/SiO2 as a Reusable Catalyst

Development of novel and green NiFe2O4/geopolymer nanocatalyst based on bentonite for synthesis of imidazole heterocycles by ultrasonic irradiations

Geopolymers as aluminosilicate inorganic polymers and eco-friendly building materials which can be used as substrate for different kinds of composite. In this research, according to the fabrication of geopolymer based on bentonite as a substrate and embedment of NiFe2O4 nanoparticles in the construction of this polymer, the synthesis of a new magnetic nanocomposite (NiFe2O4/geopolymer) was investigated for the first time. In order to describe its chemistry and morphology features, different analyses such as Fourier transform infrared spectroscopy, field-emission scanning electron microscopy and transmission electron microscopy images, Brunauer-Emmet-Teller adsorption-desorption isotherm, X-ray diffraction pattern, energy-dispersive X-ray analysis, thermogravimetric analysis, and vibrating-sample magnetometer analysis were used. The application of this novel nanocatalyst was studied for one-pot three-component condensation reaction of substituted imidazole derivatives by accelerated ultrasonic irradiations. Compared to the other conventional catalysts which were used for the synthesis of imidazole derivatives, the green synthesis method for fabrication of this heterogeneous and magnetic nanocatalyst, its high thermal stability, being eco-friendly, noticeable efficiency and easy reusability have become privileges to be superior.

Synthesis of 2,4,5-trisubstituted imidazoles, quinoxalines and 1,5-benzodiazepines over an eco-friendly and highly efficient ZrO2–Al2O3 catalyst

Where, R is alkyl, aryl, alkoxy, N,N-diethyl or halo group.

β-Cyclodextrin-Propyl Sulfonic Acid Catalysed One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles as Local Anesthetic Agents

Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. The local anesthetic effect of these derivatives was assessed in comparison to lidocaine as a standard using a rabbit corneal and mouse tail anesthesia model. The three most potent promising compounds were subjected to a rat sciatic nerve block assay where they showed considerable local anesthetic activity, along with minimal toxicity. Among the tested analogues, 4-(1-benzyl-4,5-diphenyl-1H-imidazol-2-yl)-N,N-dimethylaniline (5g) was identified as most potent analogue with minimal toxicity. It was further characterized by a more favourable therapeutic index than the standard.