2,3-Bis(isovaleroyloxymethyl)quinoxaline 1,4-di-N-oxide 2,3-Quinoxalinediylbis(methylene) 3-methylbutanoate N,N'-dioxide 63751-58-6 Butanoic acid, 3-methyl-, 2,3-quinoxalinediylbis(methylene) ester, N,N'-dioxide