title: A convenient route to 4-carboxy-4-anilidopiperidine esters and acids.
abstract: The route selection and development of a convenient synthesis of 4-carboxy-4-anilidopiperidines is described. Previous routes were hampered by the low yield of the target esters as well as the inability to convert the esters to the required free acids. Considerations for large-scale production led to a modified synthesis that utilised a tert-butyl ester of 4-carboxy-4-anilidopiperidines which resulted in a dramatic increase in the overall yield of the target N-propionylated- 4-anilidopiperidine-4-carboxylic acids and their corresponding methyl esters. These compounds are now available for use as precursors and reference standards, of particular value for the production of 11C and 18F-labelled 4-carboxy-4-anilidopiperidine radiotracers.
authors.affiliation: ABX Advanced Biochemical Compounds, Biomedizinische Forschungsreagenzien GmbH, Heinrich-Glaeser-Strasse 10-14, D-01454 Radeberg, Germany. marton@abx.de
authors.forename: János
authors.initials: J
authors.lastname: Marton
authors.forename: Brita
authors.initials: B
authors.lastname: Glaenzel
authors.forename: Julia
authors.initials: J
authors.lastname: Roessler
authors.forename: Daniela
authors.initials: D
authors.lastname: Golaszewski
authors.forename: Gjermund
authors.initials: G
authors.lastname: Henriksen
mesh_terms: D000478:Alkylation; D000701:Analgesics, Opioid / Q000138:chemical synthesis*; D002264:Carboxylic Acids / Q000138:chemical synthesis*; D060326:Chemistry Techniques, Synthetic; D003500:Cyclization; D004952:Esters / Q000138:chemical synthesis*; D005283:Fentanyl / Q000031:analogs & derivatives* / Q000138:chemical synthesis
chemical_list: D000701:Analgesics, Opioid; D002264:Carboxylic Acids; D004952:Esters; C017114:carfentanil; D005283:Fentanyl