1,3-Benzenedisulfonic acid, 4-((2,3-dihydro-3-oxobenzothiophen-2-ylidene)methyl)-, dipotassium salt 1,3-Benzenedisulfonic acid, 4-((3-oxobenzo(b)thien-2(3H)-ylidene)methyl)-, dipotassium salt 2-(2,4-Disulfobenzylidene)-3-oxo-2,3-dihydrobenzo(b)thiophene, dipotassium salt 66096-13-7 Dipotassium 4-((3-oxobenzo(b)thien-2(3H)-ylidene)methyl)benzene-1,3-disulphonate EINECS 266-141-7