反应详情

温度

0 °C

Trimethylaluminium (2M in heptane, 3 ml) was added dropwise to a solution of 2-bromoaniline (860 mg) in dichloromethane (15 ml). After gas evolution ceased, 5,6-dihydro-2H-pyridine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester (Chem. Commun. 1999, 1757-1758, 1.2 g) dissolved in dichloromethane (10 ml) was added and the resulting mixture was refluxed for 5 hrs. The solution was cooled to 0° C., quenched by careful addition of saturated aqueous sodium bicarbonate (10 ml) and extracted with dichloromethane. The organic layer was washed with brine, dried (Na2SO4) and concentrated in vacuo. The residue was purified by silica gel chromatography (eluent cyclohexane:ethyl acetate 85:15) to afford 5-(2-bromo-phenylcarbamoyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (1.2 g), which was characterised by its mass and NMR spectra.

1. additionwas added
2. temperaturethe resulting mixture was refluxed for 5 hrs
3. customquenched by careful addition of saturated aqueous sodium bicarbonate (10 ml)
4. extractionextracted with dichloromethane
5. washThe organic layer was washed with brine
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated in vacuo
8. customThe residue was purified by silica gel chromatography (eluent cyclohexane:ethyl acetate 85:15)