484-47-9Relevant articles and documents
The one-pot synthesis of 2,4,5-triaryl-imidazoles using heteropolyacids as heterogeneous and recyclable catalysts
Heravi, Majid M.,Sadjadi, Samaheh,Oskooie, Hossein A.,Hekmatshoar, Rahim,Bamoharram, Fatemeh F.
, p. 1199 - 1203 (2008)
2,4,5-triaryl imidazoles were obtained in high yields with excellent purity from the condensation of benzaldehydes, NH4OAc and 1,2-diketone in the presence of a catalytic amount of various heteropolyacids (HPAs).
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Matsuura,Ito
, p. 431 (1972)
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Tentative mechanism for the bistability observed during irradiation of the triphenylimidazolyl radical dimer in a CSTR
Borderie,Lavabre,Levy,Micheau,Laplante
, p. 4105 - 4109 (1990)
We previously reported on the observation of a bistability when a chloroform solution of the triphenylimidazolyl radical dimer (TPID) is irradiated in a CSTR (continuous now stirred tank reactor) (J. Phys. Chem. 1988, 92, 16). In the present paper, the photochemistry of TPID in chloroform is examined in more detail and key reactions are summarized in a 6-step mechanism. Values of relevant kinetic parameters are determined and used in numerical simulations of the TPID/CHCl3 photochemistry in a CSTR. Multiple steady states are indeed observed when experimental values of the kinetic parameters arc used in the simulations. The bistability width and transition points are in good agreement with experimental results. It is suggested that the feedback mechanism responsible for the instability is of photometric origin. One of its key components is the screen effect that arises as the result of competitive absorption in multicomponent photochemical systems.
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Gallas Novas et al.
, p. 633,636 (1955)
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Magnetic horsetail plant ash (Fe3O4@HA): a novel, natural and highly efficient heterogeneous nanocatalyst for the green synthesis of 2,4,5-trisubstituted imidazoles
Hosseini Mohtasham, Nina,Gholizadeh, Mostafa
, p. 2507 - 2525 (2021/03/24)
Horsetail plant ash (HA), as a natural source of mesoporous silica, has been prepared from the exposure of horsetail plant (Equisetum Arvense) to high temperature. In the present study, a new magnetically separable and also recoverable Fe3O4 nanoparticles were synthesized in the presence of natural horsetail plant ash (HA) as a support to result in Fe3O4@HA. FT-IR, XRD, TEM, SEM–EDX and VSM analysis were combined to characterize the morphology and structure of this novel synthesized nanocatalyst. This magnetically solid acid nanocatalyst showed an excellent catalytic activity for the synthesis of 2,4,5-trisubstituted imidazoles at room temperature in aqueous media. The procedure led to corresponding products in high to excellent yields and appropriate times. Additionally, this nanocatalyst can be easily recovered by a magnetic field and reused for six other consecutive reaction runs without noticeable loss of its catalytic efficiency. Based on this study, Fe3O4@HA is found to be an efficient, magnetically separable, recyclable, and green catalyst with natural source. Graphic abstract: In this work, horsetail plant ash was used as a natural source of mesoporous silica for the synthesis of Fe3O4@HA as a highly powerful magnetically solid acid nanocatalyst, which was fully characterized using various techniques. The activity of the newly synthesized nanocatalyst was tested for the synthesis of 2,4,5-trisubstituted imidazole derivatives.[Figure not available: see fulltext.]
Homoselective synthesis of 5-substituted 1H-tetrazoles and one-pot synthesis of 2,4,5-trisubstuted imidazole compounds using BNPs@SiO2-TPPTSA as a stable and new reusable nanocatalyst
Khodamorady, Minoo,Ghobadi, Nazanin,Bahrami, Kiumars
, (2021/02/22)
Considering the importance of tetrazole and imidazole derivatives in pharmacy, industry, and explosives, BNPs@SiO2-TPPTSA was easily prepared and used as an effective, stable, and renewable nanocatalyst for the homoselective synthesis of different 5-substituted 1H-tetrazoles and atom economic synthesis of 2,4,5-trisubstituted-1H-imidazoles in solventless conditions. BNPs@SiO2-TPPTSA was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), thermal gravimetric-differential thermal analysis (TGA-DTA), mapping, pH analysis, and Fourier transform infrared (FT-IR) techniques. Furthermore, the catalyst recycled for at least sequential five loads without a remarkable drop-in catalytic activity.
TMSOTf-catalyzed synthesis of trisubstituted imidazoles using hexamethyldisilazane as a nitrogen source under neat and microwave irradiation conditions
Asressu, Kesatebrhan Haile,Chan, Chieh-Kai,Wang, Cheng-Chung
, p. 28061 - 28071 (2021/09/15)
In the process of drug discovery and development, an efficient and expedient synthetic method for imidazole-based small molecules from commercially available and cheap starting materials has great significance. Herein, we developed a TMSOTf-catalyzed synthesis of trisubstituted imidazoles through the reaction of 1,2-diketones and aldehydes using hexamethyldisilazane as a nitrogen source under microwave heating and solvent-free conditions. The chemical structures of representative trisubstituted imidazoles were confirmed using X-ray single-crystal diffraction analysis. This synthetic method has several advantages including the involvement of mild Lewis acid, being metal- and additive-free, wide substrate scope with good to excellent yields and short reaction time. Furthermore, we demonstrate the application of the methodology in the synthesis of biologically active imidazole-based drugs.
