Diethyl 2-<i>tert</i>-butyl-4,11-dioxo-2,3-dihydro-<i>cis</i>-1<i>H</i>,5<i>H</i>,10<i>H</i>-2,3a,4a,10a,11a-pentaazabenzo[<i>f</i>]indeno[2,1,7-<i>ija</i>]azulene-11b,11c-dicarboxylate
Acta crystallographica. Section E