Fast routine production of l-[11C-methyl]methionine with Al2O3KF

✍ Scribed by Frédéric Schmitz; Alain Plenevaux; Guy Del-Fiore; Christian Lemaire; Dominique Comar; André Luxen

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 441 KB
• Volume: 46
• Category: Article
• ISSN: 0969-8043
• DOI: 10.1016/0969-8043(95)00181-c

✦ Synopsis

No-carrier-added (nca) L-["C-methyl]methionine was prepared via the very fast S-alkylation of L-homocysteine adsorbed on AI203/KF with ["C]iodomethane at room temperature in ethanol. The alkylation was realized with a radiochemical yield of 94 _+ 4% EOB (n = 20). More than 90% (n = 20) of the precursor L-homocysteine remained adsorbed on the solid support and was eliminated by a simple filtration. After reaction, neither racemization nor by-product were detected. The purification process was thus limited to a C18 Sep-Pak followed by an alumina Sep-Pak. The radiochemical purity measured on the final solution was shown to be > 99%. The only chemical contaminant was L-homocysteine (+ 10 #g). With this new technique, L-[HC-methyl]methionine was ready for injection within 10 min from [NC]CO2 with a specific activity ranging around 37 + 5.6 GBq (I _+ 0.15 Ci)//tmol EOB. Through this procedure L-[uC-methyl]methionine can be prepared without preparative HPLC purification, This is an important simplification for the fast routine production of one of the most widely used radiopharmaceutical compounds for PET.