Regiospecific N9 Alkylation of 6-(Heteroaryl)purines: Shielding of N7 by a Proximal Heteroaryl C−H<sup>1</sup>
作者:Minghong Zhong、Morris J. Robins
DOI:10.1021/jo061759h
日期:2006.11.1
agents. Treatment of 6-(2-butylimidazol-1-yl)-2-chloropurine (9) with sodium hydride in DMF followed by addition of ethyl iodide resulted in exclusive formation of 6-(2-butylimidazol-1-yl)-2-chloro-9-ethylpurine (10), whereas identical treatment of 2-chloro-6-(4,5-diphenylimidazol-1-yl)purine (11) produced a regioisomeric mixture 12/13 (N9/N7, ∼5:1). The linked imidazole and purine rings are coplanar