N-benzoyl-5-methyl-[5'-O-(4,4'-dimethoxytrityl)-2'-O-(2-trifluoroacetamido)ethyl-β-D-ribofuranosyl]cytosine 、
bis(2-cyanoethyl) phosphorochloridite 、
N,N-二异丙基乙胺 以
四氢呋喃 为溶剂,
反应 3.0h,
以85%的产率得到N-benzoyl-5-methyl-{3'-O-[2-cyanoethyl(diisopropylamino)phosphanyl]-5'-O-(4,4'-dimethoxytrityl)-2'-O-(2-trifluoroacetamido)ethyl-β-D-ribofuranosyl}cytosine