disodium 4-[(3-carboxylato-4-hydroxy-1-naphthyl)phenylmethylene]-1,4-dihydro-1-oxo-2-naphthoate

4-[[4-Hydroxy-3-(sodiooxycarbonyl)-1-naphthalenyl]phenylmethylene]-1-oxo-1,4-dihydronaphthalene-2-carboxylic acid sodium salt