TRITIUM-LABELED CHOLINE COMPOUNDS

Methods are developed for preparing tritium-labeled choline chloride, acetylcholine chloride, phosphorylcholine chloride, and chlorocholine chloride. The H-3 label is introduced into [H-3-CH3]choline chloride through quaternization of dimethylethanolamine by high-activity [H-3]methyl iodide. Acylation, phosphorylation, and chlorination of [H-3-CH3]choline chloride are used to synthesize acetyl[H-3-CH3]choline chloride, [H-3-CH3]phosphorylcholine chloride, and [H-3-CH3]chlorocholine chloride. The compound [H-3-CH3CO]acetylcholine chloride is prepared by acylation of dimethylethanolamine with high-activity [H-3]acetic anhydride and subsequent quaternization of the labeled intermediate. The molar activity of the synthesized labeled compounds is 1480-2960 TBq/mole (40-80 kCi/mole).