4-ethylamino-6-methyl-7,7-dioxo-4,5,6,7-tetrahydro-7lambda6-thieno[2,3-b]thiopyran-2-sulfonic acid amide
(4S,trans)-4-(ethylamino)-6-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-2-sulfonamide 7,7-dioxide