A simple synthesis of [ 11C]carfentanil using an extraction disk instead of HPLC

Abstract

[ 11C]Carfentanil was prepared without the need for purification by HPLC. The tetrabutylammonium salt of the precursor carboxylate was reacted with [ 11C]methyl triflate in DMSO. The resulting [ 11C]carfentanil was trapped on an Empore extraction disk and washed to remove precursor and most radioactive contaminants. The product was eluted by a small volume of ethanol, mixed with water and passed through a small column containing fibrous anion exchanger to remove remaining radioactive contaminants.