Used as a coupling reagent in peptide synthesis, facilitating the formation of amide bonds between amino acids. It is particularly effective in solid-phase peptide synthesis due to its high reactivity and ability to minimize racemization. Commonly employed in the preparation of pharmaceuticals, biochemical probes, and research compounds where precise peptide sequences are required. Also utilized in the synthesis of labeled peptides for diagnostic applications. Its chloride salt form enhances stability and solubility in polar solvents, making it suitable for use in automated synthesizers.