Notes: 4-Piperidone (hydrochloride hydrate) (Item No. 21961) is an analytical reference standard categorized as a piperidine. It is a starting material in the synthesis of fentanyl (hydrochloride) (Item Nos. ISO60197 / 14719) with phenethylbromide (Item No. 20087). The physiological and toxicological properties of this compound are not known. This product is intended for research and forensic applications.