(R)-(1,3-Dihydro-1,3-dioxo-2H-isoindol-2-yl)butanedioic acid 62249-41-6 Butanedioic acid, (1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-, (R)- N-Phthaloyl-D-aspartic acid