13108-52-6

22963-62-8

13108-52-6

General procedure for the synthesis of 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine from 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine: 2,3,5,6-tetrachloro-4-mercapto-pyridine (10 g, 38.0 mmol) was dissolved in dichloromethane (DCM) (80 mL), and cooled in an ice water bath. M-chloroperoxybenzoic acid (14.4 g) was added in three batches over 15 minutes, with each batch evenly spaced. The reaction solution was stirred and reacted at room temperature for 3 h. The complete reaction of the raw material was confirmed by GC assay. After the reaction was completed, the reaction solution was washed with saturated sodium carbonate solution (2×20 mL), the organic phase was dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain the crude product. To the crude product was added ethanol (5 mL), filtered and dried to obtain 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine (10.8 g, 96% yield).