Hydrogen Peroxide → Modafinil acid

Participants

Reaction Steps

To a suspension of benzhydrylthioacetic acid (63.7 g, 0.246 mol) in methanol (250 mL) was added a solution of concentrated H2SO4 (1.6 mL) in isopropyl alcohol (65 mL) at room temperature (about 22 degrees C.). To this suspension was added 30% H2O2 in water (65 mL) drop wise over 25 minutes. The reaction was monitored by TLC and was completed within 2 hours. The solution was diluted with a solution of NaHSO3 (125 mg) in water (700 mL). The resulting precipitate was filtered, washed with water, then methanol: water (1:1), and dried to give benzhydrylsulfinylacetic acid (47.6 g). 1H-NMR indicated the desired product was obtained along with ˜10 percent starting material and some impurities. The compound was triturated with ethanol (100 mL), filtered and dried to give pure benzhydrylsulfinylacetic acid (33.4 g, 49.4%) as a colorless solid. (See Prisinzano, T. et al, Tetrahedron Asymm., 2004, 15, 1053-1058)

Provenance & Evidence