117077-85-7Relevant articles and documents
One-pot multicomponent reaction of catechols, ammonium acetate, and aldehydes for the synthesis of benzoxazole derivatives using the fe(iii)-salen complex
Sharghi, Hashem,Aboonajmi, Jasem,Aberi, Mahdi
, p. 6567 - 6577 (2020)
The Fe(III)-salen complex has been applied successfully as a catalyst for the novel, simple, efficient, and one-pot multicomponent synthesis of benzoxazole derivatives from catechols, ammonium acetate as the nitrogen source, and aldehydes (nontoxic and cheap alternatives of amines) for the first time. Using this procedure, a wide range of benzoxazoles was successfully synthesized in the presence of a catalyst in EtOH under mild conditions, and all products were obtained in excellent yields. To the best of our knowledge, this method is the first example of the multicomponent synthesis of benzoxazole derivatives using these starting materials. The notable features such as the use of air that is considered as a benign oxidant and EtOH as a green solvent, ease of product separation, readily available and inexpensive aldehydes, and mild conditions make our procedure more efficient and practical for organic synthesis. Moreover, the current protocol is successfully applied to synthesize desirable products on a large scale.
Consecutive Oxidation/Condensation/Cyclization/Aromatization Sequences Catalyzed by Nanostructured Iron(III)-Porphyrin Complex towards Benzoxazole Derivatives
Aberi, Mahdi,Aboonajmi, Jasem,Sharghi, Hashem,Shiri, Pezhman
, p. 5978 - 5984 (2020)
A facile, efficient, and eco-friendly strategy to access benzoxazole heterocyclic products has been accomplished through oxidation of catechols followed by condensation/cyclization/aromatization sequences. This process is catalyzed by nanostructured iron(III)-porphyrin complex to form desired benzoxazole derivatives at room temperature under air condition. The procedure is widely applicable to diverse amines, and can provide the heterocyclic products in a scalable fashion, as well. One of the most significant types of oxidizing agents in nature is the iron-porphyrin complexes (0.1 mol-%), existing in the structure of hemoglobin. They have benefits such as low toxicity and high oxidation potential for many substrates.
Synthesis method for preparing benzoxazole compound from catechol compound, ammonium acetate and aldehyde compound
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Paragraph 0051-0053, (2021/09/01)
The invention provides a synthesis method for preparing a benzoxazole compound by oxidizing a catechol compound, ammonium acetate and an aldehyde compound with sodium periodate under a metal-free condition. According to the method, a series of compounds with benzoxazole frameworks are prepared from cheap and easily available raw materials under mild conditions. In the method, sensitive functional groups such as hydroxyl, carboxyl and amido can be well tolerated; and besides, iodate after the reaction can be well recovered, so that the pollution caused by a reaction system is greatly reduced, the atom economy of the reaction is improved, and meanwhile, the problems of environmental pollution caused by heavy metals and metal residues in the product are avoided. According to the method, benzoxazole frameworks with various structures can be simply constructed, and the method has very important significance and application value for synthesis and application research of the compounds.
Synthesis method for preparing benzoxazole compound by oxidizing catechol compound with oxygen
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Paragraph 0050-0053, (2021/08/19)
The invention provides a method for synthesizing a benzoxazole compound through reaction of a catechol compound and a primary amine under oxygen oxidation. The method has the characteristics of cheap and easily available raw materials, simple reaction system, easy separation of the obtained target product, simple reaction operation, safety, reliability and the like. Compared with the prior art, the method has the advantages that oxygen is used as the cleanest and mildest oxidizing agent, meanwhile, water widely existing in the nature is mainly used as a solvent, an expensive metal catalyst and an oxidizing agent which is difficult to treat do not need to be used, and the economic cost is reduced. The invention provides a cleanest synthesis method for the basic skeleton of the benzoxazole compound required in the fields of medicines, materials and the like, and has a huge application value.
