Reaction mass of pentasodium 2-{[4-chloro-6-(ethyl{3-[(2-sulfonatoethyl)sulfonyl]phenyl}amino)-1,3,5-triazin-2-yl]amino}-5-hydroxy-6-({2-sulfonato-4-[(4-sulfonatophenyl)diazenyl]phenyl}diazenyl)naphth