4-phenoxyacetylamino-1-[2-(2'deoxy-β-D-ribofuranosyl)ethyl]-2-(2-octylthioethyl)-6-oxopyrimidine 、
4,4'-双甲氧基三苯甲基氯 在
吡啶 作用下,
以90%的产率得到4-phenoxyacetylamino-1-[2-(2'deoxy-5'-O-(4,4'-dimethoxytrityl)-β-D-ribofuranosyl)ethyl]-2-(2-octylthioethyl)-6-oxopyrimidine