1,20-Diazido-3,6,9,12,15,18-hexaoxaeicosane is an intermediate in the synthesis of O-(2-Aminoethyl)-O’-[2-(Boc-amino)ethyl]pentaethylene Glycol (A608865), a heterobifunctional polyethyleneglycol (PEG) derivative used in the preparation of intramolecular linking agents.