2,3-dibromo-3-(2-nitrophenyl)propanoic acid

4,5,6,7,4',5',6',7'-octahydro-1H,1'H-[2,2']biindolylidene-3,3'-dione

2-ethoxycarbonyl-1,2-dihydroindol-3-one

4-(2-nitro-phenyl)-2-oxo-but-3-enoic acid

2-(carboxymethyl-amino)-4-sulfo-benzoic acid