An alternative synthesis of [11C]raclopride for routine use.

The standard method of [11C]raclopride synthesis requires a large amount of its desmethyl precursor. We prepared [11C]raclopride by methylation of a small amount of desmethyl derivative (0.3-0.5 mg) with [11C]methyl iodide in a DMF solution containing NaH, with a decay-corrected radiochemical yield of 11-14% based on [11C]methyl iodide and with a specific activity of 48 TBq/mmol for 25 min from EOB. The reaction was reproducible and reliable.