Synthesis and cell culture studies on the antiviral activity of 5-mercaptomethyl-2'-deoxyuridine.

Treatment of 5-mercaptomethyluracil (I) with trimethylsilyl chloride in the presence of triethylamine gave 2,4,5-tris-(trimethylsilyl)-5-mercaptomethyluracil (II) which, upon coupling with 2-deoxy-3,5-di-O-(p-toluoyl)-D-erythro-pentofuranosyl chloride, furnished as anomeric mixture of fully substituted 2'-deoxy ribonucleosides. The nucleoside with beta configuration (III) was predominantly formed and was isolated as a crystalline solid. The free nucleoside IV was obtained by removal of blocking groups by sodium methoxide catalyzed deacylation, deionization under reducing atmosphere, and chromatography on neutral alumina. IV is oxidized to the corresponding disulfide V in solution in the absence of thiols. IV was found to be markedly inhibitory against the herpes virus of infectious bovine rhinotracheitis (IBR). Against this virus, IV was found to be as potent as 5-iododeoxyuridine and cytosine arabinoside when added 18 hr before virus infection.