1H-Pyrazole-3-carboxylic acid, 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-((4-sulfophenyl)azo)-, compds. with N,N'-di(phenyl, o-tolyl andxylyl)guanidine (1:3) 97392-94-4 EINECS 306-731-4