2-Isoindolinemalonic acid, 1,3-dioxo-, diethyl ester 5680-61-5 AI3-18227 Diethyl phthalimidomalonate EINECS 227-138-6 Ethyl phthalimidomalonate NSC 12023 Propanedioic acid, (1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-, diethyl ester