1-Piperidinyloxy, 4-((2-(dimethylamino)ethyl)amino)-2,2,6,6-tetramethyl-, (Z)-2-butenedioate (2:1) 95211-90-8 N,N'-Dimethyl-N'-(2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl)-1,2-diaminoethane Ro 31-2655 Ro-31-2665