Used primarily in peptide synthesis, this compound serves as a protected derivative of aspartic acid. It facilitates the incorporation of aspartic acid into peptide chains while preventing unwanted side reactions. The Boc (tert-butyloxycarbonyl) group protects the amino group, and the OtBu (tert-butyl ester) group safeguards the carboxyl group. The ONp (para-nitrophenyl ester) moiety enhances reactivity, making it easier to form peptide bonds. This reagent is particularly valuable in solid-phase peptide synthesis, where selective deprotection and coupling steps are critical. Its application ensures efficient and controlled assembly of complex peptides, especially in pharmaceutical research and production of bioactive peptides.