Process for purifying 2-amino-6-chloro-9-(1'S,2'R)-1',2'-bis(hydroxymethyl)cyclopropane-1'-ylmethylpurine

摘要

A process for purifying 2-amino-6-chloro-9-[(1'S,2'R)-1',2'-bis(hydroxymethyl) cyclopropane-1'-yl]methylpurine represented by the following formula (5) comprises the step of selectively isolating 2-amino-6-chloro-9-[(1'S,2'R)-1',2'-bis(hydroxymethyl) cyclopropane-1'-yl]methylpurine from a mixture of 2-amino-6-chloro-9-[(1'S,2'R)-1',2'-bis(hydroxymethyl)cyclopropane-1'-yl]methylpurine and 2-amino-6-chloro-7-[(1'S,2'R)-1',2'-bis(hydroxymethyl)cyclopropane-1'-yl]methylpurine represented by the following formula (6) by the crystallization. This process has a satisfactory medicinal quality on an industrial scale without necessitating complicated operations such as chromatographic purification.