Nucleophilic analytes, detection

In different types of condensed polycyclic systems, mostly nitrogen-containing systems, the elimination of attached fluorine by thiols has proved a valuable synthetic tool for the introduction of sulfur moieties. In 4-(aminosulfonyI)-7-fluoro-2,l,3-benzoxadiazole(l) the reactivity of the fluorine towards sulfur nucleophiles is sufficiently high that it can be used analytically for the detection of thiols14 (c.g., in peptides). The reaction proceeds almost quantitatively. 

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