Anti-Covid-19 Drug Analogues: Synthesis of Novel Pyrimidine Thioglycosides as Antiviral Agents Against SARS-COV-2 and Avian Influenza H5N1 Viruses

[Image: see text] A class of pyrimidine thioglycoside analogs (6a–h) were synthesized from a reaction of 2-cyano-3,3-dimercapto-N-arylacrylamide (2a–d) and thiourea to produce the corresponding 4-amino-2-mercapto-N-arylpyrimidine-5-carboxamide derivatives (3a–d), and stirring of compounds (3a–d) with peracylated α-d-gluco- and galacto-pyranosyl bromides (4a,b) in DMF–sodium hydride gave the corresponding pyrimidine thioglycosides (5a–h). Deacetylation of the pyrimidine thioglycosides via a reaction with dry NH(3)/MeOH gave the corresponding free pyrimidine thioglycosides (6a–h). The compounds have been characterized by (13)C NMR, (1)H NMR, and IR. Pharmacological evaluation of compounds 3a–d, 5a–h, and 6a–h in vitro against SARS-COV-2 and Avian Influenza H5N1 virus strains revealed that some compounds possess interesting activity.