Synthesis of acyclonucleosides of imidazole and purine series.

In order to search for improved syntheses of 9-(2-hydroxyethoxymethyl) guanine and related antiviral agents, we tried several well documented general procedures (viz., fusion method) for the synthesis of N-glycosyl bond. Product distribution on alkylation of 4,5-disubstituted imidazoles as well as 2,6-disubstituted purines may depend upon the nature of alkylating agents (viz., 2-oxa-1,4-butanediol diacetate or 1-bromo-2-oxa-4-butanol acetate) and reaction conditions. A procedure for the synthesis of acyclovir and its N2-acetyl derivative could be improved to a considerable extent.