反应详情

A solution of 3-chloroquinoxaline-2-carbonyl chloride (1.0 g, 4.40 mmol) in dichloromethane (9.2 mL) was added dropwise to a mixture of tert-butyl 4-aminobenzoate (851.0 mg, 4.40 mmol), pyridine (1.07 mL, 13.21 mmol) and dichloromethane (13.8 mL) at 0° C. The reaction was stirred and allowed to warm up to room temperature over 40 minutes. To the reaction, water (10 mL) was added. The two layers were separated. The organic layer was washed with water (2×10 mL), dried over Na2SO4, filtered and the solvent was evaporated under reduced pressure. The product was slurried in hexanes at 40° C., and the solid was isolated by filtration to yield tert-butyl 4-[(3-chloroquinoxaline-2-carbonyl)amino]benzoate (1.34 g, 79%) as a yellow solid. ESI-MS m/z calc. 383.10, found 384.4 (M+1)+; Retention time: 1.88 minutes (3 minutes run). 1H NMR (400 MHz, DMSO-d6) δ 11.28 (s, 1H), 8.27 (dd, J=7.5, 2.1 Hz, 1H), 8.22-8.11 (m, 1H), 8.11-8.01 (m, 2H), 7.97 (d, J=8.8 Hz, 2H), 7.86 (d, J=8.7 Hz, 2H), 1.56 (s, 9H) ppm.

1. additionwas added
2. customThe two layers were separated
3. washThe organic layer was washed with water (2×10 mL)
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. customthe solvent was evaporated under reduced pressure
7. customwas slurried in hexanes at 40° C.
8. customthe solid was isolated by filtration