Mild and regiospecific synthesis of 18F-labelled vinyl fluoride using [18F]flourine reacted with silane

Abstract

A labelled vinyl fluoride of biological interest was prepared in good radiochemical yield by direct fluorination of the corresponding silane. The synthesis of ¹⁸F-labelled 4-fluoroantipyrine, a cerebral blood flow tracer, involved the reaction of 4-(trimethylsilyl) antipyrine with [¹⁸F]F₂ (0.5% fluorine in neon) or 5% F₂ in nitrogen in freon-11 as solvent. A radiochemical (chemical) yield of about 18% (42%) was obtained in a 25-min synthesis. The radiochemical and chemical purity of the final products was 99% after purification by HPLC.