反应详情

A solution of 6-bromo-quinoline-3-carboxylic acid (500 mg, 1.98 mmol) and triethylamine (3.97 mmol) in tertbutanol (2 mL) was degassed by bubbling nitrogen for 5 min, and DPPA (3.97 mmol, 858 mg) was added. The reaction mixture was stirred at reflux for 4 h. The solvent was removed in vacuo, and the residue was partitioned between water and ethyl acetate. The aqueous layer was extracted with ethyl acetate (2×), and the combined organics were washed sequentially with a saturated aqueous solution of sodium bicarbonate and brine, dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was by flash chromatography using a gradient of 0-10% methanol/dichloromethane to afford 347 mg of (6-bromo-quinolin-3-yl)-carbamic acid tert-butyl ester (54% yield): 1H NMR (DMSO-d6) δ 1.53 (s, 9H), 7.69 (dd, 1H), 7.85 (d, 1H), 8.21 (d, 1H), 8.48 (s, 1H), 8.85 (d, 1H), 10.00 (bs, 1H); MS (m/z) 325 [M+H]+.

1. customby bubbling nitrogen for 5 min
2. temperatureat reflux for 4 h
3. customThe solvent was removed in vacuo
4. customthe residue was partitioned between water and ethyl acetate
5. extractionThe aqueous layer was extracted with ethyl acetate (2×)
6. washthe combined organics were washed sequentially with a saturated aqueous solution of sodium bicarbonate and brine
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo