A New Synthesis of Acyclovir Prodrugs. N 2-Acetylacyclovir and 6-Deoxyacyclovir
17 September 2002 (online)
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.