A SERIES OF NOVEL ACYCLIC NUCLEOSIDES I : SYNTHESIS OF 5-AMINO-3-[(2-HYDROXYETHOXY)METHYL]-3H-IMIDAZO[4, 5-d][1, 3]OXAZIN-7-ONE

Abstract

A novel acyclic nucleoside (4) that N¹ of acyclovir (3) is replaced by oxygen atom was prepared. 5-Amino-1-[(2-acetoxyethoxy)methyl]-4-ethoxycarbonylimidazole (6a) was treated with ethoxycarbonyl isothiocyanate to give compound (7). Methylation of 7 with MeI afforded S-methylisothiourea derivative (8). Treatment of the latter with alkali followed by neutralization afforded 5-amino-3-[(2-hydroxyethoxy)methyl]-3H-imidazo[4, 5-d][1, 3]oxazin-7-one (4).