反应详情

Add isopropyl chloroformate (36.9 mL, 36.9 mmol, 1.0 M in toluene) dropwise to a solution of methyl 2-amino-5-bromobenzoate (5.0 g, 24.6 mmol) and pyridine (80.0 mL, 36.9 mmol) in dichloromethane (80 mL) at room temperature under an atmosphere of nitrogen and stir for 1.5 h. Pour the reaction into water (100 mL) and separate the layers. Extract the aqueous layer with dichloromethane (2×40 mL) and combine the organic extracts and wash with 2 N hydrochloric acid, saturated sodium hydrogen carbonate, and brine (80 mL each). Dry the organic layer over anhydrous sodium sulfate, filter, and remove the solvent under reduced pressure to afford the title compound as a pale yellow solid (6.68 g, 86%). 1H NMR (CDCl3) δ 1.31 (d, J=6.3 Hz, 6H), 3.92 (s, 3H), 5.03 (septet, J=6.3 Hz, 1H), 7.61 (dd, J=1.9, 8.5 Hz, 1H), 8.11 (d, J=1.9 Hz, 1H), 8.40 (d, J=8.5 Hz, 1H), 10.31 (br s, 1H). ESI MS m/z 316 [C12H14BrNO4+H]+.

1. additionPour
2. customseparate the layers
3. extractionExtract the aqueous layer with dichloromethane (2×40 mL)
4. washwash with 2 N hydrochloric acid, saturated sodium hydrogen carbonate, and brine (80 mL each)
5. dry with materialDry the organic layer over anhydrous sodium sulfate
6. filtrationfilter
7. customremove the solvent under reduced pressure