Radiofluorination with 18F-labelled acetyl hypofluorite: [18F]L-6-fluorodopa

Acetyl hypofluorite labelled with 18F was produced in glacial acetic acid from [18F]F2 gas diluted with neon. L-3-Methoxy-4-hydroxyphenylalanine ethyl ester hydrochloride was reacted with the acetyl hypofluorite either in glacial acetic acid or in a mixture of glacial acetic and trifluoroacetic acids at room temperature for 20 min. After hydrolysis of the reaction products with 48% hydrobromic acid, L-[18F]6-fluorodopa (4%, EOB, radiochemical yield) was isolated by reverse phase high pressure liquid chromatography. Despite its low yield the method may be useful for the production of L-[18F]6-fluorodopa with which the dopamine rich regions of the brain can be demonstrated and with which dopamine metabolism can be measured by positron emission tomography.