Used in solid-phase oligonucleotide synthesis as a phosphoramidite building block for introducing modified nucleosides into DNA strands. Enables incorporation of protected purine derivatives with specific stereochemistry, useful in antisense oligonucleotide therapeutics, siRNA, and diagnostic probes. The benzamido group stabilizes the nucleobase during synthesis, while the bis(4-methoxyphenyl)(phenyl)methoxy moiety acts as a hydroxyl protecting group, allowing stepwise chain elongation. The 2-cyanoethyl group facilitates phosphate protection and is easily removed under mild conditions. Ideal for automated DNA synthesizers in research and pharmaceutical development.