9-(2-Acetoxyethoxy)-2-amino-1,9-dihydro-6H-purin-6-one (1b) and 2-acetylamino-9-(2-hydroxyethoxy)methyl-1,9-dihydro-6H-purin-6-one (N2-acetylacyclovir 3) were prepared from 9-[(2-acetoxyethoxy)methyl] -2-acetylamino-1,9-dihydro-6H-purin-6-one (1a) using regioselective deacetylation procedures. Compounds 1a and 1b were chlorinated with phosphoryl chloride to give 9-[(2-acetoxyethoxy)methyl]-2-acetylamino-6-chloro-9H-purine (4a) and its N2-deacetylated counterpart (4b), respectively. Subsequent reductive dechlorination of 4a and 4b under conditions of catalytic transfer hydrogenolysis followed by deprotection afforded 6-deoxy-acyclovir (7) in a good overall yield.
9-(2-乙酰氧基乙氧基)-2-
氨基-1,9-二氢-
6H-嘌呤-6-酮(1b)和 2-乙酰
氨基-9-(2-羟基乙氧基)甲基-1、9-[(2-acetoxyethoxy)methyl] -2-乙酰
氨基-1,9-二氢-
6H-嘌呤-6-酮 (1a)采用区域选择性脱乙酰化程序制备出 9-[(2-乙酰氧基乙氧基)甲基] -2-乙酰
氨基-1,9-二氢-
6H-嘌呤-6-酮 (N2-acetylacyclovir 3)。化合物 1a 和 1b 经
磷酰
氯氯化后,分别得到 9-[(2-乙酰氧乙氧基)甲基]-2-乙酰
氨基-6-
氯-9H-
嘌呤(4a)及其 N2-脱乙酰基对应物(4b)。随后在催化转移氢解条件下对 4a 和 4b 进行还原脱
氯,再进行脱保护处理,可得到 6-脱氧-
阿昔洛韦(7),总收率很高。