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).
                                    制备了一种新型无环核苷(4),其中
阿昔洛韦(3)的 N1 被氧原子取代。5-
氨基-1-[(2-乙酰氧基乙氧基)甲基]-4-乙氧羰基
咪唑(6a)经异
硫氰酸乙氧羰基酯处理后得到化合物(7)。用 MeI 将 7 甲基化,得到 S-甲基异
硫脲衍
生物 (8)。后者经碱处理后中和,得到 5-
氨基-3-[(2-羟基乙氧基)甲基]-3H-
咪唑并[4, 5-d][1, 3]恶嗪-7-酮 (4)。