51093-74-4Relevant academic research and scientific papers
Click Variations on the Synthesis of 2-Nitrophenyl-4-aryl-1,2,3-triazoles without Isolation of 2-Nitrophenyl Azides
Cisnetti, Federico,Roux, Amélie
supporting information, p. 610 - 614 (2020/03/27)
We report a series of efficient procedures to prepare 2-nitrophenyl-4-aryl-1,2,3-triazoles avoiding the isolation of potentially hazardous 2-nitrophenyl azides. An organocatalyzed azide-enolate variant allows efficient access to the target compounds while
SNAr azidation of phenolic functions utilizing diphenyl phosphorazidate
Ishihara, Kotaro,Shioiri, Takayuki,Matsugi, Masato
supporting information, (2019/12/27)
A useful method for the synthesis of aryl azides via SNAr reaction of phenol derivatives using diphenyl phosphorazidate (DPPA) as an azidation reagent was developed. Various phenol derivatives bearing electron-withdrawing groups were converted into the corresponding aryl azides in a single step. This method is easy to perform and enables the preparation of aryl azides without the use of explosive azide sources.
Hypoxia-Selective Agents Derived from Quinoxaline 1,4-Di-N-oxides
Monge, Antonio,Palop, Juan A.,Cerain, Adela Lopez de,Senador, Virginia,Martinez-Crespo, Francisko J.,et al.
, p. 1786 - 1792 (2007/10/02)
Hypoxic cells, which are a common feature of solid tumors, but not normal tissues, are resistant to both anticancer drugs and radiation therapy.Thus the identification of drugs with selective toxicity toward hypoxic cells is an important objective in anticancer chemotherapy.The benzotriazine di-N-oxide (SR 4233, Tirapazamine) has been shown to be an efficient and selective cytotoxin for hypoxic cells.Since the bioreductive activation of Tirapazamine is thought to be due to the presence of the 1,4-di-N-oxide moiety, a series of 3-aminoquinoxaline-2-carbonitrile 1,4-di-N-oxides with a range of electron-donating and -withdrawing substituents in the 6- and /or 7- positions has been synthesized and evaluated for toxicity to hypoxic cells.Electrochemical studies of the quinoxaline di-N-oxides and Tirapazamine showed that as the electron-withdrawing nature of the 6(7)-substituent increases, the reduction potential becomes more positive and the compound is more readily reduced.Apart from the unsubstituted 6a and the 6,7-dimethyl derivative 6c, the quinoxaline di-N-oxide have reduction potentials significantly more positive than Tirapazamine (Epc -0.90 V).The most potent cytotoxins to cells in culture were the 6,7-dichloro and 6,7-difluoro derivatives 6i and 6l, which were 30-fold more potent than Tirapazamine.The 6(7)-fluoro and 6(7)-chloro compounds, 6e and 6h, showed the greatest hypoxia selectivity.Four of the compounds, 6e, 6f, 6h and 6i, killed the inner cells of multicellular tumor spheroids in vitro.In vivo Balb/c mice tolerated a dose of these four compounds twice the size of that of Tirapazamine.This study demonstrates that quinoxaline 1,4-di-N-oxides could provide useful hypoxia-selective therapeutic agents.
