Abstract: In response to the high chemical oxygen demand (COD) of wastewater in the existing preparation process of thiadiazole derivatives,a new green process for preparation of thiadiazole derivatives was developed,using deionized water instead of ethanol as the reaction solvent, and introducing phase transfer catalyst to promote solid-liquid two-phase reactions.The structure of the product synthesized by the new process was characterized by infrared spectroscopy, liquid chromatography, mass spectrometry and other methods, andthe metal corrosion inhibition performance, extreme pressure performance and friction reducing performance of the synthesized product were evaluated by copper plate corrosion test and four ball test. The results showed that the COD of the wastewater produced by the new process was 2000 mg/L, which was significantly lower than that of the traditional process (700000 mg/L), indicating that the new process could meet the requirements of green environmental protection. 2,5-bis (tertnonyldithio)-1,3,4-thiadiazole was synthesized by traditional and new processes respectively, their metal corrosion inhibition performance, extreme pressure performance, and friction reduction performance are comparable, and superior to those of T561, a commercially available thiadiazole derivative metal deactivator.

Key words: thiadiazole derivatives, synthesis process, effluent, chemical oxygen demand, phase transfer catalyst, extreme pressure performance