Prodrugs of 5‐Ethyl‐2′‐deoxyuridine, II Syntheses and Antiviral Activities of 5′‐ and 3′‐Ester Derivatives

With the aim of obtaining derivatives of the well established antiherpes compound 5‐ethyl‐2′‐deoxyuridine (1) (Aedurid©, EtUdR, EDU), which are more lipophilic and therapeutically superior, 5′‐ and 3′‐ester derivatives of 1 were synthesized. Tested in primary rabbit kidney cell cultures against various strains of herpes simplex type 1 (HSV‐1) and type 2 (HSV‐2), all EtUdR esters, with the exception of compounds 8 and 13, proved almost as active as EtUdR itself, suggesting that they were readily hydrolized.