Synthesis of brain‐targeted 5‐iodo‐, 5‐vinyl‐ and ( E )‐5‐(2‐iodovinyl)‐2′‐deoxyuridines coupled to a dihydropyridine ⇌ pyridinium salt redox chemical delivery system

5‐Iodo‐3′‐ O ‐(1‐methyl‐1,4‐dihydropyridyl‐3‐carbonyl)‐2′‐deoxyuridine (15a) , 5‐vinyl‐3′‐ O ‐(1‐methyl‐1,4‐di‐hydropyridyl‐3‐carbonyl)‐2′‐deoxyuridine (15b) and ( E )‐5‐(2‐iodovinyl)‐3′‐ O ‐(1‐methyl‐1,4‐dihydropyridyl‐3‐carbonyl)‐2′‐deoxyuridine (15c) were synthesized for future evaluation as lipophilic brain‐selective antiviral agents for the treatment of herpes simplex encephalitis. Quaternization of the 3′‐ O ‐(3‐pyridylcarbonyl) compounds 10–11 using iodomethane afforded the corresponding 1‐methylpyridinium salts 12–13 which were reduced with sodium dithionite to yield the corresponding 3′‐ O ‐(1‐methyl‐1,4‐dihydropyridyl‐3‐carbonyl) compounds 14–15.