反应详情

温度

170 °C

To a round-bottomed flask at rt was charged with ethyl (2E)-3-(2-hydroxy-6-nitrophenyl)prop-2-enoate (Example 206, 260 mg, 1.10 mmol), N,N-dimethylformamide (2 mL), t-butyldimethylsilyl chloride (198 mg, 1.32 mmol), and imidazole (150 mg, 2.20 mmol). The resulting mixture was left stirring at rt for 2 hours before hydrochloric acid was added and the mixture was extracted with diethyl ether (2×20 mL). The combined organic layer was washed with water, brine, and dried over anhydrous sodium sulfate. The concentrated residue was used without further purification. It was mixed with triethyl phosphite (920 mg, 5.50 mmol) and heated to 170° C. for 3 hours before it was cooled to rt and diluted with ethyl acetate. The mixture was washed with water, brine and dried over anhydrous sodium sulfate. The concentrated residue was purified with silica gel flash chromatography by using hexane/ethyl acetate (3/1) as the eluant to give ethyl 4-(1,1,2,2-tetramethyl-1-silapropoxy)indole-2-carboxylate as a white solid (224 mg, 64%): Rf0.57 (3/1 hexane/ethyl acetate); %): MS (MH+) calcd for C17H26NO3Si 320.2, found 320.2; 1H NMR (DMSO-d6) δ 11.87 (br s, 1H), 6.99-7.15 (m, 3H), 6.47 (dd, J=7.3, 0.6 Hz, 1H), 4.33 (q, J=7.0 Hz, 2H), 1.33 (t, J=7.0 Hz, 3H), 1.01 (s, 9H), 0.22 (s, 6H).

1. waitThe resulting mixture was left
2. additionwas added
3. extractionthe mixture was extracted with diethyl ether (2×20 mL)
4. washThe combined organic layer was washed with water, brine
5. dry with materialdried over anhydrous sodium sulfate
6. customThe concentrated residue was used without further purification
7. temperaturewas cooled to rt
8. washThe mixture was washed with water, brine
9. dry with materialdried over anhydrous sodium sulfate
10. customThe concentrated residue was purified with silica gel flash chromatography