反应详情

To an ice-cold solution of tert-butyl (2-hydroxyethyl)methylcarbamate (3.0 g, 17 mmol), N-hydroxyphthalimide (2.8 g, 17 mmol) and triphenylphosphine (4.5 g, 17 mmol) in THF (90 mL) was added a solution of diethyl azodicarboxylate (3.0 mL, 19 mmol) in THF (15 mL) dropwise. The stirred reaction mixture was allowed to warm to ambient temperature. After 2 days, most of the THF was removed under reduced pressure. The residue was partitioned between CH2Cl2 (40 ml) and H2O (30 mL). The organic layer was separated and washed with saturated NaCl (20 ml), dried (Na2SO4) and concentrated under reduced pressure. Purification by column chromatography (silica gel, 50:50 hexanes/EtOAc) gave tert-butyl[2-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)oxy]ethyl]methylcarbamate (4.3 g, 79%) as a yellow oil: 1H NMR (300 MHz, CDCl3) δ1.46 (9H, s), 3.03 (3H, br s), 3.62 (2H, br s), 4.34 (2H, br s), 7.74-7.85 (4H, m).

1. customThe stirred reaction mixture
2. custommost of the THF was removed under reduced pressure
3. customThe residue was partitioned between CH2Cl2 (40 ml) and H2O (30 mL)
4. customThe organic layer was separated
5. washwashed with saturated NaCl (20 ml)
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated under reduced pressure
8. customPurification by column chromatography (silica gel, 50:50 hexanes/EtOAc)