反应详情

温度

50 °C

To a suspension of NaH (60%, 9.38 g, 235 mmol) in DMF (200 mL) at 0° C. under N2 is added tert-butyl ethyl malonate (45.7 mL, 243 mmol) over 30 min. The reaction is stirred for 1.5 h in an ice bath. 2-Benzyloxy-4-fluoro-1-nitrobenzene (20.0 g, 80.9 mmol) is added and the reaction heated to 50° C. for 7.5 h. The reaction is quenched with H2O (600 mL) and extracted with EtOAc (2 L). The organic phase is concentrated to ˜1 L, washed with H2O (2×500 mL) and brine (300 mL), and dried over Na2SO4. Evaporation yields a yellow oil. The oil is azeotroped with DCM and the resulting solid is triturated with a hexanes/Et2O solution, affording a yellow solid. Two additional crops of the solid are obtained from the filtrate upon standing. The solids are combined to afford 2-(3-benzyloxy-4-nitrophenyl) -malonic acid tert-butyl ester ethyl ester: MS (M−H)−=414.

1. customThe reaction is quenched with H2O (600 mL)
2. extractionextracted with EtOAc (2 L)
3. concentrationThe organic phase is concentrated to ˜1 L
4. washwashed with H2O (2×500 mL) and brine (300 mL)
5. dry with materialdried over Na2SO4
6. customEvaporation
7. customyields a yellow oil
8. customThe oil is azeotroped with DCM
9. customthe resulting solid is triturated with a hexanes/Et2O solution
10. customaffording a yellow solid
11. customTwo additional crops of the solid are obtained from the filtrate