1-Ethoxycarbonylmethyl-3-phenylhydrazinomethylenepyrrolidine-2,4-dione 1-Pyrrolidineacetic acid, 2,4-dioxo-3-((2-phenylhydrazino)methylene)-, ethyl ester 141581-90-0 Ethyl 2,4-dioxo-3-((2-phenylhydrazino)methylene)-1-pyrrolidineacetate