Nucleic acid related compounds. 37. Convenient and high-yield syntheses of N-[(2-hydroxyethoxy)methyl] heterocycles as "acyclic nucleoside" analogues

Treatment of 1,3-dioxolane with acetyl bromide gave (2-acetoxyethoxy)methyl bromide (2a) in 88% yield. A number of pyrimidines and three chloropurines were trimethylsilylated and coupled with 2a. The respective N-1 and N-9 alkylated products (obtained in 79–89% yields) were deacetylated to give N-[(2-hydroxyethoxy)methyl] heterocycles. The 6-amino or 6-chloro substituent of the 2-amino-6-substituted-purine derivatives was hydrolyzed smoothly with adenosine deaminase to give 9-[(2-hydroxyethoxy)methyl]guanine (acycloguanosine), the potent antiviral agent.