37566-40-8

4005-51-0

37566-40-8

Step 4: Synthesis of 5-chloro-1,3,4-thiadiazol-2-amine To a stirred solution of 2-amino-1,3,4-thiadiazole (0.5 g, 4.95 mmol) in carbon tetrachloride (10.0 mL) was slowly added N-chlorosuccinimide (0.73 g, 5.45 mmol) at 25 °C. The reaction mixture was warmed to 85 °C and stirred continuously for 2 hours. The reaction progress was monitored by thin layer chromatography (TLC). After completion of the reaction, the mixture was quenched with ice water and the target compounds were extracted with a dichloromethane solution of 10% methanol. The organic layers were combined, washed sequentially with water and saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the crude product. The crude product was purified by column chromatography on silica gel (100-200 mesh) with the eluent being a hexane solution of 20% ethyl acetate to afford 5-chloro-1,3,4-thiadiazol-2-amine (0.18 g, yield 26.94%) as a light brown solid. Mass spectrum (MS): 135.97 [M+H]+.