28082-85-1Relevant academic research and scientific papers
To what extent are the photophysical properties of quinoxaline- and quinoxalinone-based chromophores predictable?
Burganov, Timur I.,Katsyuba, Sergey A.,Islamova, Liliya N.,Fazleeva, Guzyal M.,Sharipova, Sirina M.,Kalinin, Alexey A.,Monari, Antonio,Assfeld, Xavier
, (2019/06/06)
A series of chromophores containing quinoxaline or quinoxalinone electron-acceptor (A) and dialkylaminostyryl electron-donor (D) units linked by π electronic bridge has been synthesized. Electronic emission and absorption spectra of the novel D-π-A, D-π-A-π-D or D-π-A-π-A-π-D systems cover a broad range from ultraviolet to near infrared. Positions and relative intensities of their absorption bands are shown to depend strongly on structural modifications of the molecules, while emission in solution strongly depends on both the structure of the solute and the solvent polarity. Quantum chemical modeling provided a reliable description of the observed absorption spectra and reproduced the positions of the emission bands. Quantum yields of emission are shown to be qualitatively predictable on the basis of empirical rules connecting the luminescence intensity with the chemical structures of both quinoxaline- and quinoxalinone-based luminopohores and the polarity of the solvents used. Theoretical assessment of the character of the main electronic transitions suggests that simultaneous presence of D and A units conjugated via π-bridges ensures the intramolecular charge-transfer effects probably underlying the observed similar solvatochromism for all the studied systems irrespective of their polarity.
Unexpected imidazoquinoxalinone annulation products in the photoinitiated reaction of substituted-3-methyl-quinoxalin-2-ones with N-phenylglycine
De La Fuente, Julio R.,Canete, Alvaro,Jullian, Carolina,Saitz, Claudio,Aliaga, Christian
, p. 1335 - 1345 (2013/11/19)
Photoinduced electron transfer between N-phenylglycine (NPG) and electronically excited triplets of 7-substituted-3-methyl-quinoxalin-2-ones in acetonitrile generate the respective ion radical pair, where by decarboxylation the phenyl-amino-alkyl radical, PhNHCH2?, is generated. This radical reacts with the 3-methyl-quinoxalin-2-ones ground states, leading to the product 2. Other, unexpected, 7-substituted-1,2,3,3a-tetrahydro-3a-methyl-2- phenylimidazo[1,5-a]quinoxalin-4(5H)-ones, annulation products, 3a-f, were generated; likely by the addition of two PhNHCH2? radicals, to positions 3 and 4 of the quinoxalin-2-ones. The reaction mechanism includes a photoinduced one electron transfer initiation step, propagation steps involving radical intermediates and NPG with radical chain termination steps that lead to the respective products 2a-f and 3a-f and NPG by-products. The proposed mechanism accounts for the strong dependency found for the initial photoconsumption quantum yields on the electron-withdrawing power of the substituent. Therefore, photolysis of common reactants widely used such as NPG and substituted quinoxalin-2-ones may provide a simple synthetic way to the unusual, unreported tetrahydro-imidazoquinoxalinones 3a-f.
TRIAZOLOPYRAZINE DERIVATIVES AND THEIR USE FOR TREATING NEUROLOGICAL AND PSYCHIATRIC DISORDERS
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Page/Page column 20, (2013/03/26)
The present invention is directed to triazolopyrazine compounds of Formula (I). Separate aspects of the invention are directed to pharmaceutical compositions comprising said compounds and uses of the compounds as therapeutic agents treating neurological and psychiatric disorders.
Crystal structures of 3-methyl-2(1H)-quinoxalinone and three substituted derivatives
Mondieig, Denise,Negrier, Philippe,Massip, Stephane,Leger, Jean Michel,Jarmoumi, Chakir,Lakhrissi, Brahim
experimental part, p. 1193 - 1200 (2012/03/10)
3-Methyl-2(1H)-quinoxalinone and three derivatives (3,7-dimethyl-2(1H)- quinoxalinone, 3-methyl-6,7-dichloro-2(1H)-quinoxalinone and 3-methyl-7-nitro-2(1H)-quinoxalinone) have been synthesised and analysed by 1H NMR and IR spectral spectroscopies. The crystal structures have been determined at room temperature from X-ray single crystal diffraction data for three of them and from powder diffraction data for the nitro derivative. 3-Methyl-2(1H)-quinoxalinone crystallises in the P21/c monoclinic system, 3,7-dimethyl-2(1H)-quinoxalinone in the Pbca orthorhombic system and the two others compounds in the P1 triclinic system. For the nitro derivative, C-H..N short contacts are established between the carbon of the methyl and the double bounded nitrogen of the ring. For the three other compounds N-H..O hydrogen bonds involve the atoms of the heterocyclic ring. Copyright
Synthesis of some novel 2,4-disubstituted thiazoles as possible antimicrobial agents
Wagle, Shivananda,Adhikari, Airody Vasudeva,Kumari, Nalilu Suchetha
body text, p. 1285 - 1300 (2009/04/16)
A series of 4-aryl-2-(3-methyl-7-substituted quinoxaline-2-one-1-yl)-1,3- thiazoles (6a-l) and 4-substituted alkyl-2-(3-methyl-7-substituted quinoxaline-2-one-1-yl)-1,3-thiazoles (8a-i) were synthesized in good yield by condensing 2-(3-methyl-7-substituted l,2-oxoquinoxalin-1(2H)-yl)ethanethioamides (5a-c) with substituted phenacyl bromide and dichloroacetone followed by treatment with secondary amines, respectively. The intermediates, 5a-c were conveniently obtained by reacting phosphorus pentasulphide with 2-(3-methyl-7-substituted-2-oxoquinoxalin-1(2H)-yl) acetamides (4a-c) which in turn were synthesized from ethyl (3-methyl-7-substituted-2-oxoquinoxalin-1(2H)- yl) acetates (3a-c) by aqueous ammonia treatment. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, and Mass spectral and elemental analyses. These compounds were screened for in vitro antibacterial activity against five pathogenic strains and antifungal activity against four fungi. Preliminary results revealed that some of the synthesized compounds showed promising antimicrobial activity. Copyright Taylor & Francis Group, LLC.
Synthesis of some new 2-(3-methyl-7-substituted-2-oxoquinoxalinyl)-5-(aryl) -1,3,4-oxadiazoles as potential non-steroidal anti-inflammatory and analgesic agents
Wagle, Shivananda,Adhikari, Airody Vasudeva,Kumari, Nalilu Suchetha
, p. 439 - 448 (2008/09/20)
Ethyl (3-methyl-7-substituted-2-oxoquinoxalin-1(2H)-yl) acetates 2a-c are prepared by the condensation of ethyl chloroacetate with 3-methyl-7-substituted quinoxalin-2(1H)-ones 1a-c. The reaction of 2a-c with hydrazine hydrate furnished 2-(3-methyl-7-substituted-2-oxoquinoxalin-1(2H)-yl) acetohydrazides 3a-c, which on cyclisation with substituted aromatic carboxylic acids in the presence of phosphorous oxychloride give 3-methyl-7-substituted-1-[(5-aryl-1,3, 4-oxadiazol-2-yl)methyl]quinoxalin-2(1H)-ones 4a-y. Further, the compounds 3a-c on cyclisation with carbon disulphide in methanolic potassium hydroxide yielded 1-[(5-mercapto-1,3,4-oxadiazol-2-yl)methyl]-3-methyl-7-substituted quinoxalin-2(1H)-ones 5a-c. Finally, the compounds 5a-c are converted to 3-methyl-7-substituted-1-{[5-(alkylsulfanyl)-1,3,4-oxadiazol-2-yl]methyl} quinoxalin-2(1H)-ones 6a-i by reacting them with different alkyl halides. The newly synthesized compounds have been characterized by IR, 1H NMR, 13C NMR and mass spectral data and elemental analysis. Selected compounds are screened for in vivo anti-inflammatory and analgesic activity. Few of them exhibited promising activity.
