A captive solvent method for rapid N-[11C]methylation of secondary amides: application to the benzodiazepine, 4'-chlorodiazepam (RO5-4864).
[11C]4'-Chlorodiazepam (RO5-4864), for PET studies of peripheral benzodiazepine receptors, was synthesized by alkylation of 1-desmethyl-4'-chlorodiazepam, in a small volume of acetone adsorbed on acrylic yarn, with [11C]methyl iodide in the injection loop of a liquid chromatograph. The reaction mixture was introduced directly onto a small, disposable alumina chromatographic column. Elution with pentane:ethanol gave a product of high chemical and radiochemical purity. A simple heating and cooling device for the injection loop is described.
Watkins
G L
GL
Cyclotron/PET Facility, University of Michigan Medical School, Ann Arbor 48109-0552.
Jewett
D M
DM
Mulholland
G K
GK
Kilbourn
M R
MR
Toorongian
S A
SA
D001570:Benzodiazepinones; D002250:Carbon Radioisotopes; D007553:Isotope Labeling / Q000379:methods*; D013997:Time Factors; D014055:Tomography, Emission-Computed
D001570:Benzodiazepinones; D002250:Carbon Radioisotopes; C028513:4'-chlorodiazepam