Used as a protected form of hydroxylamine (O-(4-nitrobenzyl)hydroxylamine) in organic synthesis, particularly for the preparation of nitrones via condensation reactions with carbonyl compounds. The 4-nitrobenzyl protecting group can be removed under mild reduction conditions, making it suitable as a protecting group for hydroxylamine in multi-step or one-pot syntheses. It serves as a key intermediate in the development of biologically active molecules, including pharmaceuticals and agrochemicals. Its ability to form stable nitrone adducts is valuable in spin-trapping applications for studying free radical mechanisms. Additionally, it is employed in the modification of biomolecules and in click chemistry for selective functionalization, as well as in systems for controlled release of active agents.