title: Synthesis and characterization of [N-methyl-3H]loperamide.
abstract: Loperamide is a piperidine butyramide mu-opiate receptor agonist and currently employed to treat diarrhea. Because a single past report of tritiating loperamide was limited to only a very low specific activity product without technical details or extensive analysis, the synthesis of [N-methyl-(3)H]loperamide at high specific activity is now described in detail. An imine precursor was alkylated with [(3)H]methyl iodide to obtain a quaternary intermediate, which was then reacted with 4-(4-chlorophenyl)-4-hydroxypiperidine to afford the desired product [N-methyl-(3)H]loperamide, characterized by thin layer chromatography (TLC), HPLC, MS, UV, and proton-decoupled tritium NMR.
authors.affiliation: PerkinElmer Life Sciences & Technology Inc., 940 Winter Street, Waltham, MA, 02451, USA.
authors.forename: Crist N
authors.initials: CN
authors.lastname: Filer
authors.forename: Judith A
authors.initials: JA
authors.lastname: Egan
authors.forename: Richard P
authors.initials: RP
authors.lastname: Nugent
mesh_terms: D060326:Chemistry Techniques, Synthetic; D008139:Loperamide / Q000138:chemical synthesis* / Q000737:chemistry*; D010880:Piperidines / Q000737:chemistry; D011854:Radiochemistry; D014316:Tritium
chemical_list: D010880:Piperidines; D014316:Tritium; C032727:piperidine; D008139:Loperamide
keywords: loperamide; mu-opiate receptor; tritium; tritium NMR