Lenalidomide Impurity B 

Chemical Name: 3-(1,3-Dihydro-4-nitro-1-oxo-2H-isoindol-2-yl)-2,6-piperidinedione ; 3-(4-nitro-1-oxo-1,3-dihydro-isoindol-2yl)-piperidine-2,6-dione ; 3-(4-Nitro-1-oxo-2,3-dihydro-1H-isoindol-2yl)-piperidine-2,6-dione

Synonym: Lenalidomide 4-Nitro Impurity

Smile: O=C(C(N(CC1=C2C=CC=C1[N+]([O-])=O)C2=O)CC3)NC3=O