Trifluoroacetic anhydride → HCID 118598753, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of ethyl 5-bromo-3-chloro-1-oxido-pyridin-1-ium-2-carboxylate (3, 150 g, 534.8 mmol) in dimethylformamide (900 mL) at 0° C. was added trifluoroacetic anhydride (224.63 g, 1.07 mmol). The temperature of the reaction mixture was raised to 50° C. and stirring was continued for 1 h. After the oxidation was complete, the reaction mass was quenched with a saturated aqueous sodium bicarbonate solution and product was extracted with dichloromethane (2×100 mL). The organic layers were separated, combined, dried with magnesium sulfate and concentrated to dryness under vacuum to afford ethyl 5-bromo-3-chloro-6-oxo-1H-pyridine-2-carboxylate (4) as a yellow solid. Yield: 75 g, 50%; MS (ESI) m/z 281.8 [M+1]+; 1H NMR (400 MHz, DMSO-d6) δ 10.44-10.02 (m, 1H), 7.86 (s, 1H), 4.47 (q, J=7.2 Hz, 2H), 1.43 (t, J=5.6 Hz, 3H).

Provenance & Evidence