1-fluoro-2,4-dinitrobenzene is primarily used as a reagent in organic synthesis, particularly in nucleophilic aromatic substitution reactions. Its electron-withdrawing nitro groups make the fluorine atom highly reactive, allowing it to easily undergo substitution with nucleophiles such as amines or thiols. This property makes it valuable in the preparation of dyes, pharmaceuticals, and other complex organic compounds. Additionally, it is employed in biochemical research as a labeling agent for proteins and peptides, where it reacts with amino groups to form stable derivatives. Its role in synthesizing intermediates for agrochemicals and polymers also highlights its industrial importance.