反应详情

To a solution of (R)-tert Butoxycarbonylamino-(4-hydroxy-phenyl)-acetic acid (2.54 g, 9.55 mmol) in DMF (5 mL) was added imidazole (1.43 g, 21 mmol) followed by t-butyldimethylsilyl chloride (1.58 g, 10.5 mmol). The resulting mixture was stirred at rt for overnight. Additional t-butyldimethylsilyl chloride (1.43 g, 9.55 mmol) was added and let the reaction continue for another hour. The reaction mixture was diluted with EtOAc and washed with H2O three times and concentrated. To the residue was added aqueous 1N NaOH and then acidified with concentrated HCl. The resulting mixture was extracted with EtOAc three times. The combined organic layer was dried (MgSO4) and concentrated to provide the titled compound (4.5 g).

1. waitcontinue for another hour
2. washwashed with H2O three times
3. concentrationconcentrated
4. additionTo the residue was added aqueous 1N NaOH
5. extractionThe resulting mixture was extracted with EtOAc three times
6. dry with materialThe combined organic layer was dried (MgSO4)
7. concentrationconcentrated