4-Piperidinol, 1,3-dimethyl-4-phenyl-, propionate (ester), tartrate, (+)- 63938-86-3 NU-1831 Propionic acid, 1,3-dimethyl-4-phenyl-4-piperidyl ester, tartrate, (+)- d-beta-1,3-Dimethyl-4-phenyl-4-propionoxypiperidine d-acid tartrate