反应详情

To a solution of 6-hydroxybenzo[d]oxazol-2(3H)-one (3 g, 19.85 mmol) in dry DMF (30 mL), K2CO3 (5.54 g, 40.1 mmol) and SEM-Cl (4.79 mL, 27.0 mmol) were added. The reaction mixture was stirred at room temperature for 18 h. Solvent was removed under vacuum. The residue was dissolved in ethyl acetate, washed with water and brine, and dried over sodium sulfate. The organic layer was concentrated under vacuum and the crude product was purified by flash chromatography on silica gel using 10 to 50% ethyl acetate in hexane to give 6-hydroxy-3-((2-(trimethylsilyl)ethoxy)methyl)benzo[d]oxazol-2(3H)-one as an white solid (1.2 g, 21%). 1HNMR 400 MHz, DMSO-d6: δ ppm −0.055 (s, 9H), 0.86 (t, J=8.00 Hz, 2H), 3.58 (t, J=8.00 Hz, 2H), 5.19 (s, 2H), 6.64 (dd, J=2.40, 8.40 Hz, 1H), 6.78 (d, J=2.00 Hz, 1H), 7.10 (d, J=8.40 Hz, 1H), 9.52 (s, 1H). LCMS: R.T. 1.845 min; 280.1 [M−H].

1. customSolvent was removed under vacuum
2. dissolutionThe residue was dissolved in ethyl acetate
3. washwashed with water and brine
4. dry with materialdried over sodium sulfate
5. concentrationThe organic layer was concentrated under vacuum
6. customthe crude product was purified by flash chromatography on silica gel using 10 to 50% ethyl acetate in hexane