Abstract 3 H-Benzo [1, 2]-dithiole-3-thiones were prepared from potassium sulfide and 2- halobenzaldehydes in moderate-to-good yields, and a plausible mechanism for this catalyst- free intramolecular heteroannulation reaction has been proposed. The Knoevenagel condensation reactions of 3 H-benzo [1, 2] dithiole-3-thiones with active methylene compounds such as ethyl 2-cyanoacetate and diethyl malonate, and the three-component ...