The cyclocondensations of benzofuroxan 1a with carbonylcompounds were smoothly and efficiently carried out by the adsorption of the components on the surface of silica gel or a molecular sieve to form a 2,3-disubstituted quinoxaline 1,4-dioxide. When the reactions using a molecular sieve 3A (powder) were carried out at 90°, the actual reaction times were reduced to 0.5-2 hours. Although Duerckheimer
A series of 2-acetyl and 2-benzoyl-6(7)-substituted quinoxaline 1,4-di-N-oxide derivatives were synthesized and evaluated for in vitro antituberculosis activity. The results show that 2-acetyl-3-methylquinoxaline 1,4-di-N-oxide derivatives with chlorine, methyl or methoxy group in position 7 of the benzene moiety (compounds 2, 4 and 6, respectively) and unsubstituted (3) have good antitubercular activity, exhibiting EC90/MIC values between 0.80 and 4.29. In conclusion, the potency, selectivity and low cytotoxicity of these compounds make them valid leads for synthesizing new compounds that possess better activity. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.
Photocyclisation of 2-aroylquinoxalines; formation of coloured indolo[l,2-a]quinoxalines
作者:Adnan Atfah、Muhammad Y.、Abu-Shuheil、John Hill
DOI:10.1016/s0040-4020(01)96016-8
日期:1990.1
Synthesis of Quinoxaline 1,4-Dioxides from Benzofuroxan Proceeds Not in, But on Zeolite
Quinoxaline synthesis using Na-zeolite A as a catalyst to proceeds in a better yield than that using zeolite X. The pore diameter of zeolite X is large enough to allow the benzofuroxan derivatives access to cages, therefore part of benzofuroxan is adsorbed in the internal surface of zeolite X. Whereas the windows to the cages of Na-zeolite A are too small to allow the benzofuroxan derivatives access to the cages, therefore all the benzofuroxan is adsorbed on the external surface of zeolite. The reactions of benzofuroxans with benzoylacetone was catalyzed by zeolite proceed not in, but on zeolite.