1999 年 47 巻 4 号 p. 574-575
Mitsunobu reaction of 2, 6-dichloropurine with 2, 6-difluorobenzyl alcohol gave 2, 6-dichloro-9-(2, 6-difluorobenzyl)-9H-purine and 7-benzylated congener in 73% and 10% yield, respectively. Treatment of the former compound with ammonia gave 2-chloro-9-(2, 6-difluorobenzyl)adenine (1) in good yield. Also, 2-amino-6-chloro-purine was condensed with 2, 6-difluorobenzyl alcohol in a similar manner to afford 2-amino-6-chloro-9-(2, 6-difluorobenzyl)-9H-purine (2) as a major product. Inhibition of phosphodiesterase (PDE) isozymes by 9-(2, 6-difluorobenzyl)-9H-purines was investigated and both 1 and 2 were found to be good inhibitors of PDE2 in addition to PDE4.
