Syonyms Name: 3,3-Dichlorophenylsulfonphthalein; CPR; Chlorophenol red (0.1% in ca. 20% in ethanol); dichlorophenolsulphonephthalein; alpha-(3-chloro-4-hydroxyphenyl)-alpha-(3-chloro-4-oxocyclohexa-2,5-dienylidene)toluene-2-sulphonicacid; Chlorophenol red (0.04 in wate