1H-Pyrrole-3-propanoic acid, 5-((Z)-(1,2-dihydro-2-oxo-3H-indol-3-ylidene)methyl)-2,4-dimethyl- 210644-62-5 5-((Z)-1,2-Dihydro-2-oxo-3H-indol-3-ylidene)methyl)-2,4-dimethyl-1H-pyrrole-3-propanoic acid