Synthesis and anti-herpes virus activity of 2'-deoxy-4'-thiopyrimidine nucleosides.

A series of 5-substituted 2'-deoxy-4'-thiopyrimidine nucleosides was synthesized and evaluated as potential antiviral agents. A number of analogues such as 2'-deoxy-5-propyl-4'-thiouridine (3ii), 2'-deoxy-5-isopropyl-4'-thiouridine (3iii), 5-cyclopropyl-2'-deoxy-4'-thiouridine (3iv), 2'-deoxy-4'-thio-5-vinyluridine (3viii), and 5-(2-chloroethyl)-2'-deoxy-4'-thiouridine (3xx) were found to be highly active against herpes simplex virus type-1 (HSV-1) and varicella zoster virus (VZV) in vitro with no significant cytotoxicity. The compound with the broadest spectrum of activity was 2'-deoxy-5-ethyl-4'-thiouridine (3i) which showed significant activity against HSV-1, HSV-2, and VZV.

5-(Hydroxyimino)-4-methoxy-2-(pivaloylimino)thiazolidine-3 -acetamide, a reduced nitroheterocyclic derivative with potent schistosomicidal properties.

The synthesis and antischistosome properties of 5-(hydroxyimino)-4-methoxy-2-(pivaloylimino)thiazolidine-3- acetamide (1) are described. The compound was prepared by reduction of the nitrothiazoline (2) with stannous chloride in methanol, and represents the first example of a reduced nitroheterocyclic compound showing potent schistosomicidal properties. The possible relationship of compounds such as 1 to the as yet unidentified reduced active but toxic entities formed in vivo from nitroheterocyclics like metronidazole is discussed.