Synthesis of Reagents for the One‐Step Incorporation of Hydrazide Functionality onto the Lysine Residues of Proteins and Their Use as Linkers for Carbonyl Containing Molecules.

Two new reagents, 1 and 2, were prepared for the one step incorporation of hydrazide functionality onto the lysine residues of proteins. Their utility as linking reagents was demonstrated by their use in the coupling of two model aldehydes, and the anticancer agent doxorubicin, to a monoclonal antibody.