27981-70-0 EINECS 248-755-7 p-(4,5-Dihydro-4-(3-(5-hydroxy-3-methyl-1-(4-sulphophenyl)-1H-pyrazol-4-yl)but-2-enylidene)-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulphonic acid