Synonyms: Glycine, N,N'-[(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis[(6-hydroxy-3,1-phenylene)methylene]]bis[N-(carboxymethyl)-,tetrasodium salt (9CI); Glycine,N,N'-[3H-2,1-benzoxathiol-3-ylidenebis[(6-hydroxy-3,1-phenylene)methylene]]bis[N-(carboxymethyl)-,S,S-dioxide, tetrasodium salt; 3H-2,1-Benzoxathiole, glycine deriv.;Phthalexon-S tetrasodium salt