Synthesis of Bis-Acyclonucleoside Analogues Bearing Benzothienyl-1,2,4-Triazol-3-Yl-Disulfide under Conventional and Microwave Methods

The oxidation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-thiol (1) with a solution of iodine and potassium iodide at room temperature afforded [5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-yl]disulfide (2). In contrast, when the reaction mixture was heated or irradiated by MW, an unexpected additional product was obtained and identified as 3-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole (3); the ratio of products was 3:1. The preferred conformer of 2 was deduced from the theoretical calculation. The alkylation of compounds 2 and 3 with epichlorohydrin and hydroxyalkylating agents gave the corresponding N,N-bis- and N-acyclonucleosides analogues 8-15.