Dimethyl Sulfoxide → 4-Fluoro-2-methylsulfinylbenzaldehyde

Participants

Reaction Steps

To a stirred solution of 4-fluoro-2-methylsulfanylbenzaldehyde (9.7 g, 57 mmol) in CH2Cl2 (300 mL) was added in small portions m-chloroperbenzoic acid (60%, 20.71 g, 120 mmol) over 20 minutes. After 24 h, mL of dimethylsulfoxide followed by saturated NaHCO3 (100 mL) was added and stirred for additional 2 h. The organic layer separated and washed with saturated NaHCO3 (2×100 mL). The combined aqueous layers were saturated with NaCl and extracted with CH2Cl2 (2×100 mL). The combined organic phases were dried over anhydrous Na2SO4, filtered and concentrated to give a viscous yellow oil. This residue was purified by flash chromatography on a silica gel column using hexanes/ether/ethyl acetate (gradient elution). The fractions containing the desired product are combined and concentrated to give 4-fluoro-2-methylsulfonylbenzaldehyde (3.85 g, 33%) and 4-fluoro-2-methylsulfinylbenzaldehyde (5.61 g, 53% yield) as a white solid. 4-fluoro-2-methylsulfonylbenzaldehyde: 1HNMR (500 MHz, CDCl3) δ: 10.41 (1H, s), 8.08–8.06 (1H, M), 7.85–7.71 (2H, m), 3.09 (3H, s). HRMS calcd for C8H6FO3S (M−H): 201.0022. found: 201.0025. 4-fluoro-2-methylsulfinyl-benzaldehyde: 1HNMR (500 MHz, CDCl3) δ: 9.97 (1H, s), 8.07–8.05 (1H, M), 7.99–7.94 (1H, m), 7.36–7.33 (1H, m), 2.80 (3H, s). MS calcd for C8H8FO2S (M+H): 187.02. found: 187.02.

Provenance & Evidence