Gravar e-mail: Ethyl 5-((1E)-1-{(E)-2-[1-(4-eth­oxy­carbonyl-3-methyl-1,2-oxazol-5-yl)ethyl­idene]hydrazin-1-yl­idene}eth­yl)-3-methyl-1,2-oxazole-4-carboxyl­ate