反应详情

A solution of 4-nitrohomophthalic acid (313.12 g, 58.27 mmol, J. Amer. Chem. Soc., 1969, 91, 2467) in dry THF (291 mL) under N2 is treated with NaBH4 (6.61 g, 174.8 mmol) portionwise over 15 mins. The resulting mixture is cooled in an ice bath and BF3.Et2O (22.15 mL, 174.8 mmol) is added dropwise over 35 mins. The cooling bath is removed, and the reaction mixture is stirred vigorously at ambient temperature for 18 hrs and is then cooled in an ice bath, quenched by the slow addition of 1N aqueous NaOH (233 mL, 4 equiv.) and stirred at ambient temperature for an additional 4 hrs. The THF is then removed under reduced pressure, the resulting precipitate is isolated by filtration, the filtrate is extracted with MeOH/CH2Cl2 (10/90, 3×150 mL), and the precipitate is combined with the organic extracts, diluted with additional MeOH/CH2Cl2 (10/90, 400 mL), dried over anhydrous Na2SO4, concentrated under reduced pressure and recrystallized from EtOAc/hexane to give 8.16 g (71%) of the title compound as a beige solid, mp 80-81° C. (decomp.).

1. temperatureThe resulting mixture is cooled in an ice bath
2. customThe cooling bath is removed
3. temperatureis then cooled in an ice bath
4. stirringstirred at ambient temperature for an additional 4 hrs
5. customThe THF is then removed under reduced pressure
6. customthe resulting precipitate is isolated by filtration
7. extractionthe filtrate is extracted with MeOH/CH2Cl2 (10/90, 3×150 mL)
8. additiondiluted with additional MeOH/CH2Cl2 (10/90, 400 mL)
9. dry with materialdried over anhydrous Na2SO4
10. concentrationconcentrated under reduced pressure
11. customrecrystallized from EtOAc/hexane