Synthesis of phosphorodiamidate morpholino oligonucleotides by H-phosphonate method

Synthesis of T-containing phosphorodiamidate morpholino oligomers (PMO) by H-phosphonate method on solid support has been reported for the first time. Initially, 5-mer then 15-mer of T-containing PMO using H-phosphonate-T monomer was synthesized on polystyrene resin bead. The phosphonamidate backbone was oxidized by iodine-dimethylamine mixture followed by the cleavage from solid support by aqueous ammonia to obtain 15-mer T-containing PMO.