Synthesis of 2- and 3-fluorotyrosine with dilute fluorine gas

Differences in reactivity and selectivity of fluorine gas towards L-tyrosine and the O,N-diacetylated derivative of L-tyrosine methyl ester have been exploited for the synthesis of 2- and 3-fluorotyrosine. Both 2- and 3-fluorotyrosine were identified by 1H, 19F and 13C NMR spectroscopy and high resolution mass spectrometry. The short synthesis time and high reaction yields allow this procedure to be used for the incorporation of the short lived position emitting radionuclide 18F into the aromatic ring of L-tyrosine.