Dimethyl Sulfoxide → 1-(3,4-Dichlorophenyl)-2-pyridin-4-yl-ethane-1,2-dione

Participants

Reaction Conditions

Reaction Steps

To a stirring solution of methyl sulfoxide (38.3 g, 35 mL, 490 mmol) in dichloromethane (750 mL) at -78° C. was added trifluoroacetic anhydride (77 g, 52 mL, 368 mmol) dropwise. After ten minutes, 1-(3,4-dichlorophenyl)-2-pyridin-4-yl-ethane-1,2-diol (31.7 g, 112 mmol) in dichloromethane (500 mL) was added dropwise. After another ten minutes, triethylamine (70 g, 96 mL, 690 mmol) was added dropwise and the reaction mixture immediately warmed to 0° C. and poured into saturated aqueous sodium hydrogen carbonate (300 mL). The aqueous layer was extracted with ethyl acetate (3×200 mL) and the organic layers were combined, dried over anhydrous magnesium sulfate, filtered and concentrated at reduced pressure. The resulting solid was triturated with ethyl acetate to give the dione as a yellow solid (23 g). 1H NMR (300 MHz,CDCl3) d 8.90 (dd, J=3.7 and 2.9 Hz, 2H), 8.09 (d, J=1.9 Hz, 1H), 7.85-7.73 (m, 3H), 7.63 (d, J=8.3 Hz, 1H).

Provenance & Evidence