反应详情

To a stirring cold (−78° C.) solution of ethyl 3-bromo-4-cyanobenzoate (0.41 mol, 104 g) in THF (2.3 L was added dropwise a solution of diisobutylaluminum hydride (2.0 mol, 1.36 L; 1.5 M in toluene) over a period of 1.5 h. After addition was completed, the mixture was warmed to rt over a period of 3 h. The mixture was then cooled to 0–5° C. and 40 ml of acetone was added slowly. The mixture was then transferred via a cannula to a cold (0° C.) stirring aqueous solution of HCl (2.2 L 3 N) over a period of 1.5 h, maintaining the temperature of the aqueous solution below 30° C. After the transfer was completed, the mixture was stirred for another 0.25 h. The organic solution was separated and the aqueous was extracted twice with EtOAc (3 L). The combined organic extracts were washed with brine, dried with MgSO4 (anhyd.) and concentrated to give 74 g (83%) of the title compound as a light yellow solid.

1. additionAfter addition
2. temperatureThe mixture was then cooled to 0–5° C.
3. customwas then transferred via a cannula to a cold (0° C.)
4. temperaturemaintaining the temperature of the aqueous solution below 30° C
5. customThe organic solution was separated
6. extractionthe aqueous was extracted twice with EtOAc (3 L)
7. washThe combined organic extracts were washed with brine
8. dry with materialdried with MgSO4 (anhyd.)
9. concentrationconcentrated