Nitroaromatics fluorodenitration

Fluorodenitration of nitroaromatics represents an exchange duorination technique with commercial potential. For example, y -duoronittoben2ene [402-67-5] from y -dinitroben2ene [99-65-0] and KF in the presence of various promoters can be reali2ed (69—72). This is not feasible under Halex conditions with y -chlotonittoben2ene [121 -73-3]. 

Nevertheless, nucleophilic displacement of an activated aromatic nitro group by fluoride is much more common and constitutes an efficient method of linking fluorine to an aromatic ring. The availability and low cost of nitroaromatics make fluorodenitration an attractive alternative to halogen exchange for the synthesis of selectively fluorinated aromatic compounds via nucleophilic fluorination. Various salts, such as rubidium [ F]fluoride, - tctrabutylam-monium fluoride, or potassium fluoride. can be used as fluoride sources. 

Rubidium [ F]fiuoride is used as a reagent for the [ F]fluorodenitration of nitroaromatic compounds containing activating groups (e.g., CN, COR, CO2R, OH. OMe, etc.). Rubidium [ F]fluoride gives better yields than other fluoride salts, such as potassium fluoride or cesium fluoride, which are extremely hygroscopic. This method constitutes a very convenient route to [ F]fluorine-labeled aromatics, which are often required in radiopharmaceutical studies. 

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