SYNTHESIS AND EVALUATION OF ANTIVIRAL ACTIVITY OF 2'-DEOXYURIDINES WITH 5-METHYLENE-2-THIOHYDANTOIN SUBSTITUENTS IN THE 5-POSITION

1-(2-Deoxy-3,5-bis-O-(4-methylbenzoyl)-D-erythro-pentofuranosyl)-5-formyluracil (4) was synthesized from 5-formyluracil and an appropriate methyl glycoside and condensed with 2-thiohydantoin (5a) and its corresponding 3-phenyl derivative 5b to give 5-[1-(2-deoxy-3,5-bis-O-(4-methylbenzoyl)-D-erythro-pentofuranosyl)uracil-5-ylmethylene]-2-thiohydantoins 7a and 7b, respectively, in 65-70% yield. They were deprotected with sodium methoxide in methanol to give both anomers of the free nucleosides. In a different route 5-formyluracil (1) was condensed with 5b and subsequently with an appropriate methyl glycoside to give 7b.