4-Fluoro-3-nitrobenzoic acid (CAS number 453-71-4) is derived from benzoic acid having a nitro and a fluoro substituents at 3- and 4-positions. The functional groups in 4-fluoro-3-nitrobenzoic acid possess different reactivities. The carboxylic acid reacts with alcohols for esters. Fluoride substituent favors nucleophilic aromatic substitution while nitro group can be reduced to an amine as a nucleophile. The ortho-position of fluoride and nitro makes 4-fluoro-3-nitrobenzoic acid an ideal precursor for making benzimidazoles derivatives. Benzimidazoles are active pharmaceutical ingredients applied as antimicrobials, opioids, antipsychotics and antihistamines. Benzoselenazoles (similar to benzimidazole, one nitrogen is replaced by a selenium atom) can be synthesized from 4-fluoro-3-nitrobenzoic acid reacting with isoselenocyanate.
It is feasible to attach various polymers to 4-fluoro-3-nitrobenzoic acid for block-co-polymers, in order to construct polymersomes.