2-[2-(2-Chloroethoxy)ethoxy]ethanol was used in the synthesis of 1-[3-(2-aminoethyl)-1H-indol-5-yloxy]-3,6-dioxa-8-mercaptooctane[1]. It was also used in the synthesis of modified oligonucleotides bearing a disulfide or a thiol function at the 3′-end and other modifications at the 5′-end