Used in the synthesis of modified RNA oligonucleotides, particularly in mRNA vaccine development and therapeutic RNA applications. The 2'-O-methyl pseudouridine modification enhances RNA stability, reduces immunogenicity, and improves translational efficiency when incorporated into mRNA. The DMT (dimethoxytrityl) group enables solid-phase oligonucleotide synthesis by providing reversible protection for the 5'-hydroxyl group, allowing stepwise chain elongation. The CE (cyanoethyl) phosphoramidite group facilitates efficient coupling and is later removed during standard deprotection. This phosphoramidite building block is essential for producing high-quality, modified RNA with improved pharmacological properties for use in vaccines, gene therapies, and functional genomics.