A sustainable and efficient protocol for the synthesis of imidazole-2-thione derivatives is herein reported.
The method relies on the reaction of imidazolium salts with sodium sulfide (Na2S) in water at room
temperature under visible-light irradiation. In this transformation, cobalt phthalocyanine (CoPc) serves as
an inexpensive and robust catalyst, while ambient air acts as a clean and environmentally benign terminal
oxidant. Operational simplicity, straightforward work-up, and excellent product yields highlight the
practicality of this environmentally friendly methodology, making it an attractive approach for the green
synthesis of imidazole-2-thiones.