Reduction of the N-Propargyl Group with Tritium. General Procedure for the Preparation of N-3H>Allyl Opiate Ligands at High Specific Activity

Article abstract of DOI:10.1021/jo00337a029

Radiolabeled neurotransmitter receptor ligands are exceedingly valuable substances for obtaining information about their respective receptors, and a number of them possess the N-allyl group.A method is outlined to prepare (-)-N-(<2,3-(3)H>allyl)nalloxone (1b), (-)-N-(<2,3-(3)H>allyl)nalorphine (2b), and (+/-)-N-(<2,3-(3)H>allyl)normetazocine (3b) from their respective N-propargyl precursors.Triton nuclear magnetic resonance studies confirm labeling specificity.This labeling strategy affords the highest specific activities for such ligands reported to date and possesses a number of other advantages over previous methods.Utilization of such tritiated ligands for receptor binding assay will undoubtedly lead to a more comprehensive mapping of and increased information about their respective receptors.