3,4-Ethylenedioxothiophene-2,5-dicarboxylic acid

3,4-ethylendioxythiophen-2,5-dicarbonsure ; 3,4-ethylenedioxothiophene-2,5-dicarboxylic acid ; 3,4-ethylenedioxythiophene-2,5-dicarboxylic acid ; 2,5-dicarboxylic acid-3,4-ethylene dioxythiophene ; 2,3-dihydro-thieno[3,4-b]-p-dioxin-5,7-dicarboxylic acid ; thieno[3,4-b]-1,4-dioxin-5,7-dicarboxylicacid,2,3-dihydro- ; 2,3-dihydrothieno[3,4-b][1,4]dioxine-5,7-dicarboxylic acid ; 2, 5 - dicarboxylic acid - 3, 4 - thiophene ethylene 2 oxygen