m-Chloroperbenzoic acid → 1-(4-Fluorophenyl)-2-(4-methylsulfonylphenyl)ethanone

Participants

Reaction Steps

To a stirred solution of 1-(4-fluorophenyl)-2-(4-methylthiophenyl)ethanone (Example 1, Step 3) (15.00 g, 57.62 mmol) in methylene chloride (500 mL) at 5° C. (ice-bath) was added MCPBA (29.64 g, ca. 67% peroxide, ca. 113 mmol), portionwise over 30 minutes. The solution was warmed to room temperature. The reaction solution was stirred vigorously with NaHSO3 solution for 10 minutes to quench any unreacted MCPBA. The layers were separated and ethyl acetate was added to aid in dissolution of the precipitate which began to form. The partial suspension was filtered and the solid saved. The organic phase was washed successively with NaHCO3 solution and brine, dried over Na2SO4, and diluted with isooctane until a solid began to precipitate. Upon removal of most of the ethyl acetate and methylene chloride in vacuo more solid precipitated. All of the precipitates were combined yielding 1-(4-fluorophenyl)-2-(4-methylsulfonylphenyl)ethanone (14.5 g, 86%). mp 182°-183° C. 1H NMR (CDCl3) 300 mHz δ8.04 (dd, J=5.24, 8.46, 2H), 7.92 (d, J=8.26 Hz, 2H), 7.46 (d, J=8.46 Hz, 2H), 7.17 (t, J=8.46, 2H), 4.37 (s, 2H), 3.05 (s, 3H). MS: m/z 293 (MH+); HRMS A =1.6 mmu.

Provenance & Evidence