Ethanedioic acid, mono(4,9-dihydro-4,9-dioxonaphtho[2,3-d]thiazol-2-yl)hydrazide, monoethyl ester NSC637693 Oxalic acid, mono(4,9-dihydro-4,9-dioxonaphtho[2,3-d] thiazol-2-yl)hydrazide, monoethyl ester