1,2,5,9b-Tetrahydro-4-methylnaphtho(2,1-b)thiophene-6,9-dione 3,3-dioxide 125219-84-3 4-Methyl-3,3,6,9-tetraoxo-1,2,5,6,9,9b-hexahydrothieno(3,2-a)naphthalene BRN 3556101 Naphtho(2,1-b)thiophene-6,9-dione, 1,2,5,9b-tetrahydro-4-methyl-, 3,3-dioxide