3164-06-5Relevant academic research and scientific papers
A rapid method for the preparation of 2-substituted oxazolo[4,5-b]pyridines using microwave-assisted direct condensation reactions
Myllym?ki, Mikko J.,Koskinen, Ari M.P.
, p. 2295 - 2298 (2007)
The condensation reaction of 2-amino-3-hydroxypyridine with different carboxylic acids by microwave-assisted heating is a fast method for producing libraries based on fused 2-substituted oxazolo[4,5-b]pyridines in moderate to good yields.
Tuning the Excited State of Tetradentate Pd(II) and Pt(II) Complexes through Benzannulated N-Heteroaromatic Ring and Central Metal
Fang, Xiaoli,Guo, Hua,Li, Guijie,Lou, Weiwei,She, Yuanbin,Sun, Yulu,Yang, Yun-Fang,Zhang, Qisheng
, p. 223 - 234 (2021/12/16)
A series of tetradentate Pd(II) and Pt(II) complexes containing fused 5/6/6 metallocycles with phenyl N-heteroaromatic benzo[d]imidazole (pbiz), benzo[d]oxazole (pboz) or benzo[d]thiazole (pbthz)-containing ligands was developed. Systematic studies by exp
2-Aryl benzazole derived new class of anti-tubercular compounds: Endowed to eradicate mycobacterium tuberculosis in replicating and non-replicating forms
Datta, Dhrubajyoti,Debnath, Joy,Franzblau, Scott G.,Ghosh, Kalyan Sundar,Hari, Natarajan,Ma, Rui,Rana, Shiwani,Velappan, Anand Babu
, (2020/09/04)
The high mortality rate and the increasing prevalence of Mtb resistance are the major concerns for the Tuberculosis (TB) treatment in this century. To counteract the prevalence of Mtb resistance, we have synthesized 2-aryl benzazole based dual targeted molecules. Compound 9m and 9n were found to be equally active against replicating and non-replicating form of Mtb (MIC(MABA) 1.98 and 1.66 μg/ml; MIC(LORA) 2.06 and 1.59 μg/ml respectively). They arrested the cell division (replicating Mtb) by inhibiting the GTPase activity of FtsZ with IC50 values 45 and 64 μM respectively. They were also capable of kill Mtb in non-replicating form by inhibiting the biosynthesis of menaquinone which was substantiated by the MenG inhibition (IC50 = 11.62 and 7.49 μM respectively) followed by the Vit-K2 rescue study and ATP production assay.
Synthesis and characterization of a novel oxo-bridged binuclear iron(iii) complex: Its catalytic application in the synthesis of benzoxazoles using benzyl alcohol in water
Safaei, Elham,Alaji, Zahra,Panahi, Farhad,Wojtczak, Andrzej,Jagli?i?, Janez Zvonko
supporting information, p. 7230 - 7236 (2018/05/07)
In the present work, the synthesis and characterization of a novel binuclear oxo-bridged iron(iii) complex, (FeLAPIP)2O, where LAPIP is the deprotonated form of a tetradentateo-aminophenol-iminopyridine ligand, is described. The iron complex was characterized using different techniques including X-ray crystallography, infrared spectroscopy, UV-Vis, magnetic susceptibility and cyclic voltammetry. The X-ray structure analysis revealed that in the structure of the (FeLAPIP)2O complex, each iron(iii) is coordinated in a distorted square pyramidal arrangement by an oxo group, three amine nitrogens and one oxygen atom of the o-aminophenolate ligand. The variable-temperature magnetic measurement exhibits strong antiferromagnetic coupling between two iron(iii) centers. Cyclic voltammetry measurements showed two kinds of quasireversible events, suggesting the formation of a phenoxyl radical species in the region of the anodic peaks and a metal-centered redox (FeIII/FeII) process at low potential. The catalytic activity of this Fe-complex was evaluated in coupling of 2-aminophenol and benzyl alcohols for the one-pot synthesis of benzoxazoles. The catalyst system showed high catalytic activity in this transformation and benzoxazole derivatives were obtained in good to excellent yields. tert-Butyl hydroperoxide was used as an oxidant and 1.2 mol% of catalyst was needed to accomplish the reaction in water as the green solvent.
One-pot green synthesis of benzoxazole derivatives through molecular sieve-catalyzed oxidative cyclization reaction
Chang, Weichieh,Sun, Yukai,Huang, Yungtzung
, (2017/03/08)
An one-pot approach to benzoxazole ring from 2-aminophenol and aldehydes utilizing molecular sieve as the catalyst have been developed. The new oxidative cyclization reaction excluded the usage of hazardous chemical reagents, transition-metal catalysts, chemical oxidants, or strong acids, and, therefore, reduced the production of toxic chemical waste. This offers an environmentally friendly pathway for the synthesis of various benzoxazole derivatives.
Microwave Assisted Synthesis of Two-Substituted Benzoxazoles in the Presence of Potassium Cyanide under Mild Conditions
Naeimi, Hossein,Rahmatinejad, Soraya
, p. 471 - 476 (2015/11/02)
Various two-substituted benzoxazoles were prepared using microwave-assisted reaction of 2-aminophenol with aromatic aldehydes in the presence of one equivalent of potassium cyanide as an equimolecular catalyst. Aldehydes having either electron-donating or withdrawing groups afforded the target products. The important features of this method were high yields, short reaction times and easy work up. The structure of synthesized products was characterized by nuclear magnetic resonance (NMR) and infrared (IR).
A mild, efficient and reusable solid phosphotungestic acid catalyst mediated synthesis of benzoxazole derivatives: A grinding approach
Patil, Mahadeo R.,Yelamaggad, Aditya,Keri, Rangappa S.
, p. 474 - 481 (2016/11/19)
Background: The development of efficient methodologies for the preparation of benzoxazole and its derivatives has gained a lot of importance in current research. There are many methods are reported for the synthesis of benzoxazoles includes condensation of 2-aminophenol with carboxylic acid. Traditional methods also have several side reactions, non renewable oxidative reagents and solvents which negatively affect the environmentally and eco-friendly nature of the reaction. We have developed PTA catalyzed synthesis of 2-arylbenzoxazole from 2-aminophenols with different aromatic aldehydes using a grinding strategy in excellent yield. Methods: The synthesis of benzoxazoles in high yields by using silica supported Rangappa S. Keri PTA/PTA as solid acid catalyst at room temperature using grinding method. Results: Aromatic aldehydes which have electron donating or electron withdrawing groups were also investigated and as expected it gives good to excellent yield of products, it can be seen that electron donating and electron withdrawing groups does not show any difference on their action yields. Conclusion: We have developed PTA catalyzed synthesis of 2-arylbenzoxazole from 2-aminophenols with different aromatic aldehydes using a grinding strategy in excellent yield. The use of this reusable catalyst under solvent-free conditions has made this protocol practical, environmentally friendly and economically attractive. The simple work-up procedure, the short reaction times the mild reaction conditions, the high yields of products and the non-toxicity of the catalyst are other advantages of the present method. This protocol approaches combines the advantages of both focused library synthesis and diversity oriented synthesis because of the simplification of reaction protocol that we have been developed.
An efficient magnetic copper ferrite nanoparticle: For one pot synthesis of 2-substituted benzoxazole via redox reactions
Sarode, Sachin A.,Bhojane, Jeevan M.,Nagarkar, Jayashree M.
supporting information, p. 206 - 210 (2015/02/02)
A new, green and sustainable approach for the synthesis of 2-substituted benzoxazole by using a one pot redox cascade condensation reaction of benzyl amine and 2-nitro phenol, catalysed by Cu Ferrite NPs is reported. Cu Ferrite NPs are magnetically separable, air stable and can be recycled up to fifth cycle without a significant loss in catalytic activity. The catalyst is characterised by FEG-SEM, TEM, EDAX and XRD.
Magnetically separable nano CeO2: A highly efficient catalyst for ligand free direct C-H arylation of heterocycles
Shelkar, Radheshyam S.,Balsane, Kishor E.,Nagarkar, Jayashree M.
supporting information, p. 693 - 699 (2015/01/30)
An efficient, ligand free, nano CeO2-Fe3O4 catalyzed direct C-H arylation of heteroarenes such as benzoxazole and benzothiazole has been carried out with aryl halides in DMSO or arenediazonium salts in water. The catalyst exhibited high activity with moderate to excellent product yields under mild reaction conditions. Nano CeO2-Fe3O4 was synthesized and characterized by SEM, TEM, EDAX, XRD, FTIR, DSC-TGA, and ICP-MS analyses. The catalytic activity and stability of the catalyst were excellent, even after the ten cycle of recyclability
Graphene oxide as a heterogeneous reagent promoted synthesis of 2-substituted 1,3-benzazoles in water
Khalili, Dariush,Banazadeh, Ali Reza
, p. 1693 - 1706 (2016/01/26)
An efficient chemical method for the synthesis of benzimidazoles, benzothiazoles, and benzoxazoles has been developed through the condensation of various aldehydes with o-phenylenediamine, o-aminothiophenol, and o-aminophenol using graphene oxide (GO) as an oxidant in water. These benzazoles are also prepared through a one-pot oxidation/condensation tandem process by reacting alcohols with 2-amino-(thio)phenol/aniline in the presence of GO in poly(ethylene glycol) as a safe media. Moreover, this carbonaceous material could be readily separated using a simple filtration.
