Synthesis of no-carrier added 11C-labelled(methyl) choline analogs

We describe here the synthesis of two[11C-methyl]labelled analogs of choline and the influence of the solvent, addition of a base, and reaction time on the radiochemical yield. The reactions produced equally good yields in methanol and acetonitrile and reached maximum radiochemical yield at about 5-10 min. The addition of a base in the case of [11C-methyl]pyrrolidinocholine increases the radiochemical yield. Optimum radiochemical yields were 30% for [11C-methyl]piperidinocholine and 40% for [11C-methyl] pyrrolidinocholine for two choline analogs. (author)