1,3-Bis(4-piperidyl)propane 1,3-Di-4-piperidylpropane 16898-52-5 4,4'-(1,3-Propanediyl)bispiperidine 4,4'-Trimethylenedipiperidine DI-PIP NSC96364 Piperidine, 4,4'-(1,3-propanediyl)bis- Piperidine, 4,4'-trimethylenedi-