Synthesis of 2-Amino-6-alkoxypurine

2-Amino-6-alkoxypurine is an important intermediate of nucleotide.From guanine,through acylation,chloridization and hydrolysis,2-amino-6-chloropurine(Ⅱ,75.8% yield) was obtained Reaction of Ⅱ with a series of so dium alkoxides gave 2-amino-6-methoxypurine(Ⅲa,96.5% yield),2-amino6-ethoxypurine(Ⅲb,79.6% yield),2-amino-6-isopropoxypurine(Ⅲc,73.2% yield) and 2-amino-6-triflouroethoxypurine(Ⅲd,49.8% yield).The products were characterized by elementary analysis,~1HNMR,MS and IR.Ⅲd was studied emphatically,and the best reaction conditions were:n(Ⅱ)∶n(NaOCH_2CF_3)=1∶5,DMSO as solvent,m(DMSO)∶m(Ⅱ)=13∶1,CuI as catalyst,n(CuI)∶n(Ⅱ)=2∶1 and reaction temperature 160 ℃.