Abstract While 4-chloroxanthione 1 gives with diazomethane the dithiol 2, it reacts with other diazoalkanes to give the episulfides 3–5, desulfurization of which forms the ethylenes 6 and 7. Malononitrile and ethyl cyanoacetate react with 1 to give the cyano derivatives 8a, b. With hydrazines and p-toluidine, 4-chloroxanthione (1) give the hydrazones 9a, b and the Schiff's base 9c, respectively. The hydrazone 9a on oxidation may give either the corresponding ...