288613-85-4Relevant academic research and scientific papers
Concise preparation of 1,8-diazaanthracene-2,7,9,10-tetraones. Two alternative syntheses of the natural antifolate diazaquinomycin A
Pérez, José María,López-Alvarado, Pilar,Pascual-Alfonso, Eva,Avenda?o, Carmen,Menéndez, J. Carlos
, p. 4575 - 4583 (2000)
Treatment of compounds bearing one or two 1-dimethylamino-1,4- dihydropyridine moieties with the urea-hydrogen peroxide complex (UHP) led to their efficient aromatization. Double N-oxidation of 1,8-diazaanthraquinones thus obtained is the first example of a double N-oxidation of a diaza heterocycle by UHP in trifluoroacetic acid. Treatment of the crude double N- oxides with tosyl chloride in acetonitrile-water afforded 1,8- diazaanthracene-2,7,9,10-tetraones (including diazaquinomycin A) in 25-40% overall yields. An alternative synthesis of diazaquinomycin A was also devised, whose key steps are the hetero Diels-Alder reaction between 2- methyl-2-hexenal dimethylhydrazone and 3-methyl-4-propyl-2H-quinoline-2,5,8- trione and the oxidative functionalization of the 1,8-diazaanthracene-2,9,10- trione derivative thus obtained. (C) 2000 Elsevier Science Ltd.
