HIGH PURITY 2-AMINO-9-(2-SUBSTITUTED ETHYL) PURINE AND METHOD FOR PREPARING 9-(4-ACETOXY-3-(ACETOXYMETHYL)BUT-1-YL)-2-AMINO PURINE (FAMCICLOVIR) HAVING ANTIVIRAL ACTIVITY, EFFECTIVELY BY USING THE SAME UNDER MILD CONDITIONS

摘要

PURPOSE: Provided are 2-Amino-9-(2-substituted ethyl) purine and a method for preparing 9-(4-acetoxy-3-(acetoxymethyl)but-1-yl)-2-amino purine (famciclovir) using the same effectively under mild conditions. The famciclovir has antiviral activity. CONSTITUTION: The 2-amino-9-(2-substituted ethyl) purine is represented by the formula(II'), wherein R is hydroxy, halogen, mesyloxy or tosyloxy. The method for preparing the 2-amino-9-(2-substituted ethyl) purine represented by formula(II) comprises reacting a compound of the formula(XXIV) with a reducing agent under polar organic solvent at 0 to 100 deg. C; and reacting the resulting product with a compound of the formula (XVIII) at 50 to 150 deg. C, wherein the reducing agent is Raney-nickel and/or iron powder; and the polar organic solvent is N,N-dimethylformamide, dimethylsulfoxide, acetonitrile, pyridine, acetate and a C1-C3 lower alcohol solvent selected from methanol, ethanol and isopropanol.