Trifluoroacetic anhydride → HCID 118598619, compound

Participants

Reaction Steps

To a stirred solution of ethyl 5-bromo-3-chloro-pyridine-2-carboxylate (2, 151.0 g, 570.89 mmol) in dichloromethane (1.73 L) was added trifluoroacetic anhydride (30.0 mL, 1.14 mol) and urea hydrogen peroxide (112.69 g, 1.20 mol) at 0° C. The reaction was stirred overnight at room temperature. After completion of the reaction, the reaction mixture was neutralized with a potassium phosphate dibasic solution. A sodium bisulfite solution was added followed by extraction with dichloromethane (2×100 mL). The organic layers were separated, combined, dried with magnesium sulfate, filtered and concentrated to dryness under vacuum to afford ethyl 5-bromo-3-chloro-1-oxido-pyridin-1-ium-2-carboxylate 3 as an off white solid. Yield: 150.5 g, 94%; MS (ESI) m/z 281.8 [M+1]+; 1H NMR (400 MHz, DMSO-d6) δ 8.26 (d, J=1.2 Hz, 1H), 7.48 (d, J=1.2 Hz, 1H), 4.50 (q, J=7.12 Hz, 2H), 1.42 (t, J=12.12 Hz, 3H).

Provenance & Evidence