反应详情

温度

0 °C

To 75 mL of dry diethyl ether was added a solution of lithium aluminium hydride (4M in diethyl ether, 14 mL, 55.8 mmol), and the solution was cooled to 0° C. A solution of ethyl 4-{[tris(1-methylethyl)silyl]oxy}benzoate (Step 1, 9.0 g, 27.9 mmol) in dry diethyl ether (90 mL) was added dropwise, maintaining the temperature below 5-10° C. After the addition was completed, stirring of the reaction mixture was continued for 1 h at 0° C. Then, still at the same temperature, a saturated aqueous solution of sodium sulfate (60 mL) was added with caution. After warming to rt, the precipitate which had formed was removed by filtration, and the residue was washed with diethyl ether. The organic layer was separated from the filtrate, and the aqueous layer was extracted with diethyl ether. The combined organic layers were washed with water and brine and dried over anhydrous magnesium sulfate. After filtration, the solvent was removed in vacuo. The crude product thus obtained was purified by MPLC (silica, cyclohexane/ethyl acetate 5:1→1:1) to afford the title compound in pure form (7.38 g, 94%): 1H NMR (400 MHz, CDCl3) δ 7.21 (d, 2H), 6.87 (d, 2H), 4.60 (d, 2H), 1.56 (t, 1H), 1.23 (m, 1H), 1.10 (d, 18H); EI-MS m/z 280 (M)+; HPLC RT (Method H) 5.33 min.

1. temperaturemaintaining the temperature below 5-10° C
2. additionAfter the addition
3. temperatureAfter warming to rt
4. customthe precipitate which had formed
5. customwas removed by filtration
6. washthe residue was washed with diethyl ether
7. customThe organic layer was separated from the filtrate
8. extractionthe aqueous layer was extracted with diethyl ether
9. washThe combined organic layers were washed with water and brine
10. dry with materialdried over anhydrous magnesium sulfate
11. filtrationAfter filtration
12. customthe solvent was removed in vacuo
13. customThe crude product thus obtained
14. customwas purified by MPLC (silica, cyclohexane/ethyl acetate 5:1→1:1)