874302-76-8

111625-28-6

7693-46-1

874302-76-8

The general procedure for the synthesis of 4-nitrophenyl 2-(pyridin-2-yldithio)ethyl carbonate from 2-(pyridin-2-yldithio)ethanol and p-nitrophenyl chloroformate is as follows: 1. 2-(2-pyridinyldithio)ethanol hydrochloride (8.8 g, 39.33 mmol) was dissolved in 78 mL of dichloromethane and 2 equivalents of pyridine (80.88 mL) was added. 2. p-Nitrophenyl chloroformate (8.08 g, 40 mmol) was dissolved in 80 mL of dichloromethane and the solution was slowly added to the above mixture over 15 minutes. 3. The reaction mixture was stirred at room temperature for 15 hours and the completion of the reaction was confirmed by TLC analysis. 4. The reaction mixture was filtered to remove the precipitated pyridine hydrochloride. 5. The pale yellow clear filtrate was washed with deionized water (2 x 50 mL) to remove the dissolved pyridine hydrochloride. 6. The organic phase was dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product (13.8 g). 7. A 50 cm x 4.2 cm silica gel column was packed with silica gel 60 (250 g), equipped with a 250 mL solvent vessel. 8. The crude product was dissolved in 15 mL (10 mL + 5 mL) of dichloromethane and loaded onto the silica gel column at a flow rate of 30 mL/min. 9. A 30 mL fraction was collected and the target compound was detected by UV, resulting in 13.3 g (96% yield) of 4-nitrophenyl 2-(pyridin-2-yl disulfide)ethyl carbonate.