Used in the solid-phase synthesis of modified oligonucleotides, particularly in the development of antisense therapeutics and siRNA. The compound enables incorporation of pseudoisocytidine, a nucleoside analog that enhances duplex stability and nuclease resistance when paired with guanosine. Its protecting groups (DMF and DMT) allow for selective and stepwise addition during automated DNA/RNA synthesis. The phosphoramidite group facilitates efficient coupling to the growing nucleic acid chain. Commonly applied in research settings to study gene expression, RNA interference, and to improve the pharmacokinetic properties of therapeutic oligonucleotides.