9-(4-bromobutyl)-2-butoxy-8-methoxy-9H-purine-6-amine 、
3-哌啶甲酸乙酯 以in the same manner as step (ii) of example 1, there was obtained the object compound 295 mg as a pale yellow oil的产率得到2-butoxy-8-methoxy-9-[4-(3-ethoxycarbonylpiperidin-1-yl)butyl]adenine