101973-46-0

60682-95-3

Example 10: In a pressure-equilibrium dropping funnel, diethyl diethyl (p-toluenesulfonylmethyl) phosphonate (30% solution, 30 mL, 290 mmol, 2.9 eq.) was slowly added dropwise to a solution of sulfide Y (27.5 g, 100 mmol, 1.0 eq.) dissolved in glacial acetic acid (100 mL) over a dropwise period of 45 minutes while the reaction system temperature was The temperature of the reaction system was maintained at 50 °C. After the dropwise addition, the reaction mixture was warmed up to 85 °C and kept for 3.5 hours. Subsequently, the reaction mixture was slowly poured into a pre-cooled aqueous sodium hydroxide solution (prepared by mixing 100 mL of 50% wt NaOH with 500 mL of crushed ice) over a period of 15 minutes, ensuring that the reaction temperature did not exceed 25 °C. The reaction was carried out with dichloromethane (1 time). The products in the reaction mixture were extracted with dichloromethane (5 times), the organic phases were combined and washed with saturated sodium bisulfite solution (3 times) until the excess oxidant was completely consumed. The organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated to dryness under reduced pressure to give the crude product Z (38 g). The crude product was further purified by silica gel column chromatography (Biotage system, 340g KP-Sil column), using a mixed solvent of methyl tert-butyl ether (MTBE)/heptane (gradient elution ratio of 1:1 to 1:0) as eluent, and the final purified product Z was obtained (22.2 g, 72.5 mmol, 72.5% yield) as white solid.