An environmentally benign synthesis of substituted 4H-thiopyrans was carried out by the condensation of aromatic aldehydes, malononitrile, carbon disulfide and primary amines. Constant potential electro synthesis was carried out in an undivided cell at room temperature in the presence of lithium perchlorate as a supporting electrolyte. Clean synthesis, use of electricity instead of chemical reagents and atom economy are attractive features of the present protocol.