Sodium Hydroxide → 2-(2-Difluoromethoxy-benzylsulfonylmethyl)-4-morpholin-4-yl-4-oxo-butyric acid

Participants

Reaction Steps

4-Morpholin-4-yl-4-oxo-2-benzylsulfonylmethyl-butyric acid (1.27 g, 4.64 mmol) was dissolved in 50 mL dry EtOH and set to stir at room temperature. NaOH pellets (556 mg, 13.92 mmol) were added in one portion, and the reaction mixture was allowed to stir for 10 min. 2-(Difluoromethoxy)-benzyl bromide (1.00 g, 4.219 mmol) was then added, and the reaction mixture was allowed to stir at ambient temperature for 20 h. Upon completion (LCMS), the reaction mixture was diluted with water and the pH was lowered to ˜2. The reaction mixture was then washed 3× with EtOAc. The organic phase was concentrated in vacuo and then diluted with 100 mL aqueous MeOH. Oxone (1.58 g, 2.43 mmol) was added in one portion and the reaction was stirred at room temperature for 4 h. Conversion of sulfide to sulfone was monitored via LCMS. Upon completion, reaction was quenched by the addition of sodium thiosulfate. Salts were filtered, and the reaction mixture was washed 3× with ethyl acetate and dried over sodium sulfate. The organics were evaporated by vacuum under reduced pressure. Product was purified via HPLC. Yield: 195 mg, 19.0%. m/z (LCMS) M+ 422.1. Rf=2.42. δH 12.6 (1H, br s), 7.6–7.2 (4H, m), 7.19 (1H, s) 4.5 (2H, s), 3.5 (4H, m), 3.5 (1H, m), 3.4 (4H, m), 3.2 (2H, d), 2.75 (2H, d).

Provenance & Evidence