Application of Microreactor to the Preparation of C-11-Labeled Compounds via O-[11C]Methylation with [11C]CH3I: Rapid Synthesis of [11C]Raclopride.
A new radiolabeling method using a microreactor was developed for the rapid synthesis of [(11)C]raclopride. A chip bearing a Y-shaped mixing junction with a 200 µm (width)×20 µm (depth)×250 mm (length) flow channel was designed, and the efficiency of O-[11C]methylation was evaluated. Dimethyl sulfoxide solutions containing the O-desmethyl precursor or [11C]CH3I were introduced into separate injection ports by infusion syringes, and the radiochemical yields were measured under various conditions. The decay-corrected radiochemical yield of microreactor-derived [11C]raclopride reached 12% in 20 s at 25 °C, which was observed to increase with increasing temperature. In contrast, batch synthesis at 25 °C produced a yield of 5%: this indicates that this device could effectively achieve O-[11C]methylation in a shorter period of time. The microreactor technique may facilitate simple and efficient routine production of 11C-labeled compounds via O-[11C]methylation with [11C]CH3I.
Graduate School of Pharmaceutical Sciences, Kyoto University.
Hidekazu
H
Kawashima
Hiroyuki
H
Kimura
Yuta
Y
Nakaya
Kenji
K
Tomatsu
Kenji
K
Arimitsu
Hiroaki
H
Nakanishi
Eiichi
E
Ozeki
Yuji
Y
Kuge
Hideo
H
Saji
D002250:Carbon Radioisotopes; D006847:Hydrocarbons, Iodinated / Q000737:chemistry*; D008745:Methylation; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D020891:Raclopride / Q000138:chemical synthesis* / Q000737:chemistry
D002250:Carbon Radioisotopes; D006847:Hydrocarbons, Iodinated; D020891:Raclopride; C014055:methyl iodide