Process for preparing 9-[4-acetoxy-3-(acetoxymethyl)but-1-yl]-2-aminopurine

摘要

Disclosed is a process for preparing 9-[4-acetoxy-3-(acetoxymethyl)but-1-yl]-2-aminopurine (called Famciclovir), a drug of purine derivatives having antiviral activity. This process comprises reacting 2-aminopurine with 2-acetoxymethyl-4-bromobut-1-yl-acetate in the presence of thallium (1) ethoxide to give the desired compound. According to this process, the desired compound can be prepared in very high selectivity and purity under mild reaction conditions.