Used primarily in peptide synthesis, this compound serves as a protected form of glutamine. It is particularly valuable in solid-phase peptide synthesis (SPPS) where the Boc (tert-butyloxycarbonyl) group protects the amino group, preventing unwanted reactions during the peptide chain assembly. The ONp (para-nitrophenyl) ester acts as an activating group, facilitating the coupling of glutamine to other amino acids or peptides. This reagent is essential in the production of complex peptides, especially in pharmaceutical research and development, where precise control over peptide structure is crucial. Its application ensures high yield and purity in the synthesis of peptides for therapeutic and diagnostic purposes.