CAS No 154161-81-6 , Cyclobutenediylium,1-[(5-chloro-1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)methyl]-3-[[5-[[(2,5-dioxo-1-pyrrolidinyl)oxy]carbonyl]-1-ethyl-1,3-dihydro-3,3-dimethyl-2H-indol-2-ylidene]methyl]-2,4-dihydroxy-,bis(inner salt) (9CI)