Used in solid-phase oligonucleotide synthesis to incorporate a modified nucleobase into DNA strands. The DMT protecting group ensures stepwise addition during synthesis, while the phosphoramidite group enables efficient coupling to the growing chain. The pyrido[2,3-d]pyrimidine core acts as a fluorescent or stabilizing analog, useful in probes, primers, or antisense technologies where enhanced binding or detection is required. Commonly applied in diagnostic assays, research reagents, and development of nucleic acid-based therapeutics.