Nucleophilic aromatic substitution reactions with the fluoride ion : formation of 5-fluoro-indanones and indandiones related to atipamezole

Abstract The 5-nitro and 5-(trimethylammonium trifluoromethanesulfonyl)indanones 2a , b and the related 1,3-indandiones 3a , b have been synthesized, and the efficiency of the nucleophilic aromatic substitution reaction with fluoride ion on these substrates evaluated. The indandiones underwent aromatic substitution to afford fluoroaromatic adducts whereas the indanone substrates provided little or no fluoro-substitution product. The fluoro- indandione was subsequently reduced to the corresponding fluoroindane hydrocarbon. The synthetic sequence of nucleophilic fluorination followed by carbonyl reduction provides a rationale for the potential preparation of the radiofluorinated α 2 -adrenoreceptor ligand 5-fluoroatipamezole.