Quinoxaline Research Papers - Academia.edu (original) (raw)

Hypervalent iodine(III)-induced oxidative [4+2] annulation of o-phenylenediamines and electron-deficient alkynes under metal-free conditions has been developed. The reaction allows for direct access to quinoxalines bearing two... more

- by Youhei Takeda
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- Advanced Oxidation Processes, Hypervalent Iodine, Oxidation, Quinoxaline

Two novel donor-acceptor (D-A)-type two-dimensional (2-D) polymers of PBDTSeQ (P1) and PBDTFQ (P2) were synthesized and characterized where 4,8-bis[5-(2-ethylhexyl) thiophen-2-yl] benzo[1,2-b:4,5-b'] dithiophene (BDT) was used as the donor unit. 2,3-Bis(3,4-bis(octyloxy)phenyl)-5,8-dibromoquinoxaline was used as the acceptor moiety and selenophene and furan were utilized as π bridges. Optoelectronic properties of the polymers were examined by electrochemical and spectroelectrochemical characterizations. In cyclic voltammetry (CV) studies, both polymers were found to be ambipolar. In anodic region, oxidation potentials were observed as 1.45 V and 1.15 V for P1 and P2 respectively, while reduction potentials were 0.65 V and 0.92 V. In cathodic region, redox potentials were found to be −1.36 V/−1.32 V and −2.0 V/−1.51 V for P1 and −1.45 V/ −1.05 V and −2.15 V/−1.45 V for P2. Both polymers showed good solubility in common solvents. The synthesized polymers were used as photoactive layers in solar cell devices. P1-based device (ITO/PEDOT:PSS/ P1:PC 71 BM (1:3, w/w)/LiF/Al) provided the best performance with a PCE of 4.04%, a V OC of 0.67 V, a J SC of 13.94 mA/cm 2 , and a FF of 43.3%.

- by Seza Goker
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- Organic solar cells, Conjugated Polymers, Electrochromism, Quinoxaline

New drugs active against drug-resistant tuberculosis are urgently needed to extend the range of TB treatment options to cover drug resistant infections. Quinoxaline derivatives show very interesting biological properties (antibacterial, antiviral, anticancer, antifungal, antihelmintic, insecticidal) and evaluation of their medicinal chemistry is still in progress. In this review we report the properties and the recent developments of quinoxaline 1,4-di-Noxide derivatives as potential anti-tuberculosis agents. Specific agents are reviewed that have excellent antitubercular drug properties, are active on drug resistant strains and nonreplicating mycobacteria. The properties of select analogs that have in vivo activity in the low dose aerosol infection model in mice will be reviewed.

- by Silvia Pérez-silanes
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- Tuberculosis, Mycobacterium, Mice, Quinoxaline

Background and objectives: Antimicrobial resistance is a serious threat to global public health. The overuse and misuse of antibiotics are the most important contributing factors to development of antibiotic resistance. Thus, there is an urgent need to identify and discover new compounds against drug-resistant microorganisms. We have previously synthesized new series of 3-substituted 5H-(1,2,4)triazolo(3',4':2,3) (1,3,4)thiadiazino(5,6-b)quinoxaline derivatives (4a-4f). Here, we evaluate the antimicrobial activity of these derivatives against methicillin-resistant Staphylococcus aureus, S. aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Candida tropicalis and Candida krusei. Methods: The agar well diffusion and agar dilution methods were used for determining inhibition zone diameter and minimum inhibitory concentration during preliminary evaluation of antimicrobial activity. Results: All synthesized compounds exhibited antibacterial and antifungal activity against the tested microorganisms. Conclusion: Our findings indicate the antimicrobial potential of the six novel synthetic triazolo thiadiazin quinoxaline compounds.

A simple, highly efficient and green procedure for the condensation of aryl and alkyl 1, 2-diamines with -diketones in the presence of different catalyst at room temperature is described. And the recycled catalyst was used for the next run under identical reaction conditions. Using this method, quinoxaline derivatives as biologically interesting compounds are produced in high to excellent yields and short reaction times. Present synthesis complies with principle of Green chemistry. As part of current studies, we here in report efficient practical technique of sonication reaction (sonosynthesis). The overall progress of the reaction was monitored by TLC and characterized by IR and NMR. Compared with traditional methods, these methods are more convenient and reactions can be carried out in higher yield, shorter reaction time and milder conditions, without generation of pollution and safer to analyst. The synthesized 2, 3-diphenyle quinoxaline was confirmed by physical constant and spectroscopic studies. Low cost, reuse of worn catalyst and maximum efficiency are some advantages of this synthesis. Compared with traditional method, this method is more convenient and reactions can be carried out in higher yield, shorter reaction time and milder conditions, without generation of pollution and safer to analyst. From these features present methods can be correlated for safer and efficient synthesis of other products.

- by Lily T
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- Chemistry, Organic Chemistry, Sonochemistry, Catalyst