50899-03-1

84211-94-9

50899-03-1

4-(Ethylthio)benzaldehyde (2.46 g, 14.8 mmol) was dissolved in dichloromethane (100 mL) at 0 °C and m-chloroperoxybenzoic acid (m-CPBA, 7 g, 31.1 mmol) was added in batches with stirring. The reaction mixture was stirred continuously at 0 °C for 1 hour. Subsequently, 1M sodium hydroxide solution (35 mL) was added and stirring was continued for 10 minutes. Upon completion of the reaction, the reaction mixture was extracted with dichloromethane and the organic layer was washed with saturated brine and subsequently concentrated under reduced pressure. Unreacted m-CPBA was found to remain in the reaction by 1H NMR analysis, so the crude product was redissolved in ethyl acetate and washed five times with 1 M sodium hydroxide solution to completely remove the residual m-CPBA. finally, the organic layer was concentrated under reduced pressure to afford 2.16 g of 4-(ethylsulfonyl)benzaldehyde in 74% yield. The structure of the product was confirmed by 1H NMR (D6-DMSO): δ 10.20 (1H, s), 8.24-8.15 (4H, m), 3.44 (2H, q, J=7.4Hz), 1.16 (3H, t, J=7.4Hz).