Purine Nucleoside Analogues. 11. An Alternative Synthesis of N- and O-Alkyl Derivatives of 9- and 7-[(2-Acetoxyethoxy)methyl]-N2-acetylguanine

Abstract

Alkylations of 9- and 7-[(2-acetoxyethoxy)methyl]- N 2 -acetylguanine with alkyl halogenides in the presence of base have been investigated affording a new route to the preparation of 1, N 2 -dimethyl- as well as O 6 -benzyl-9(7)-alkoxyalkylguanines. 1 H NMR spectra revealed that the 1, N 2 -dimethyl derivatives exist as mixtures of two conformers at room temperature due to the restricted rotation about the C2-N2 bond. These findings agreed with conformational calculations.