The synthesis of a versatile handle for the purification of synthetic peptides is described. The Boc-aminoethylsulfonylethyloxycarbonyl handle is coupled to the NH2-terminus of the resin- bound peptide. Removal of the Boc group affords a free amine which can be derivatized with any of a variety of functionalities. Cleavage from the resin gives a peptide functionalized for covalent chemoselective reaction with the column support. Desired full length peptide is ...