Facile one-pot fluorination of polycyclic aromatic hydrocarbons (PAHs) with N-fluoro-2,4-dinitroimidazole; scope and limitation

Article abstract of DOI:10.1016/S0022-1139(98)00224-3

The synthetic utility of N-fluoro-2,4-dinitro-imidazole NF-2,4-DNT, a recently introduced NF fluorinating agent, has been tested for direct one-pot fluorination of several classes of polycyclic aromatic hydrocarbons, PAHs, namely pyrene, crowded alkyl(cycloalkyl)-pyrenes; hexahydro-and tetrahydro-pyrene; benzo[a]anthracene; benzo[a]-and benzo[e] pyrene; perylene; 2,7-di-tert-butylphenanthrene;chrysene; 9-imethylanthracene and anthracene, as well as trans-15:16-dimethyl-dihydropyrene: azulene[2-a]lacenaphthylene and azulene. Although the isolated yields are modest, the ease of handling of the reagent, simple operation (reflux in dichloroethane for 3 days) and the use of 1.1 equivalent of the reagent makes the procedure quite attractive for polynuclear aromatics, avoiding multi-step operations (NO₂-PAH → NH₂-PAH → N₂⁺-PAH → F-PAH) or the use of toxic or costly reagents (CF₃OF, XeF₂, etc.); it provides direct one-pot access to a variety of F-PAHs that are not readily made using: other fluorinating agents.