Diethyl dithioxomalonate InChI=1/C7H12O2S2/c1-3-8-6(10)5-7(11)9-4-2/h3-5H2,1-2H O~1~,O~3~-diethyl propanebis(thioate) propanebis(thioic acid), O~1~,O~3~-diethyl ester