Sulfite‐Induced N‐Alkylation and Thioketonization of Azoles Enable Access to Diverse Azole Thiones

The direct modification of azole skeletons enables access to drug‐like molecules. The development of a highly compatible reaction platform for this pursuit still remains challenging. Herein, we report the use of sulfite as the single electron transfer (SET) reducing agent for the activation of functionalized bromoalkanes, elemental sulfur, and imidazoliniums for the transition metal‐free and base‐free N‐alkylation and thioketonization of azoles. Excellent functional group tolerance and high synthetic efficiency proved particularly advantageous for the rapid assembly of a large array of pharmaceutically‐oriented azole thiones, many of which contain synthetically and biologically useful functional groups. The direct transformation of drug molecules (such as Ketoconazole, Econazole, and Fluconazole) into their corresponding azole thiones has also been successfully achieved. Reactions with selenium also proceeded smoothly under the optimized conditions. Successful gram‐scale reactions demonstrate the good applicability of this methodology.