title: Synthesis of C-11 iodoantipyrine for positron emission tomography.
abstract: We have developed a method for the synthesis of C-11 iodoantipyrine. Carbon-11-labeled methyl iodide, prepared from 11CO2, was used to methylate 3-methyl-1-phenyl-2-pyrazolin-5-one to form C-11 antipyrine. Following silica-gel column chromatography and iodination, radiochemical purity of the C-11 iodoantipyrine was more than 99.5%, with a 10% yield and a specific activity of 30 mCi/mumol. Preliminary animal studies showed complete cerebral extraction and local cerebral blood-flow values that were within 4.6% of those obtained using C-14 iodoantipyrine. The C-11 analog, with positron emission tomography, will facilitate local cerebral blood-flow studies in human subjects.
mesh_terms: D000818:Animals; D000983:Antipyrine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D002250:Carbon Radioisotopes; D002560:Cerebrovascular Circulation; D007553:Isotope Labeling / Q000379:methods*; D051381:Rats; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D002250:Carbon Radioisotopes; D000983:Antipyrine; C008135:iodoantipyrine