Bromine → Ethyl 2-bromo-3-(2,4-dichlorophenyl)-3-oxopropanoate

関与物質

反応手順

To a solution of ethyl 3-(2,4-dichlorophenyl)-3-oxopropanoate (3.95 g, 15.1 mmol) in dichloromethane (150 mL) was added a solution of bromine (0.935 mL, 18.2 mmol) in dichloromethane (20.0 mL) dropwise at 0° C. The solution was then stirred at room temperature for 1 hour. The reaction was quenched with 10% aqueous potassium carbonate solution, and then the layers were separated. The organic extracts were washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude oil was used directly in the next step (5.27 g, quantitative). LCMS: (AA) ES+, 341. 1H NMR (400 MHz, d1-chloroform) (2 sets of signals, keto and enol): 12.78 (s, 1H), 7.73-7.28 (m, 2 sets of 3H), 5.73 (s, 1H), 4.37 (q, J=7.28 Hz, 2H), 4.29 (q, J=7.28 Hz, 2H), 1.41 (t, J=7.03 Hz, 3H), 1.29 (t, J=7.03 Hz, 3H).

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