反应详情

To a stirred solution of naphthalene (5.8 g, 45.3 mmol) in dry THF (20 mL) was added Na (0.85 g, 37.0 mmol) under N2. After 15 minutes stirring at room temperature, the resultant green suspension was cooled to −78° C. A cooled (−78° C.) solution of 2-[5-(Toluene-4-sulfonyl)-1H-imidazol-4-yl]-pyridine (Tetrahedron Lett. 1976, 285) (1 g, 3.34 mmol) in dry THF (20 mL) was then added through a cannula. Stirring was continued at −78° C. for 30 minutes and then at room temperature for 10 minutes. The reaction was quenched with the addition of H2O at 0° C. The reaction mixture was diluted with ethyl acetate (80 mL), washed successively with H2O (50 mL) and brine (50 mL), dried over Na2SO4. After removal of the volatile components in vacuo, the residue was dissolved in dry DMF (5 mL) with stirring. NaH (60% with mineral oil, 0.2 g, 5.0 mmol) was then added. After stirring at room temperature for 15 minutes, a solution of SEM-Cl (0.58 g, 3.5 mmol) in dry DMF (1 mL) was then added slowly. After stirring at room temperature for 3 hours, the reaction mixture was poured into cold H2O (50 mL); any undissolved materials were filtered off. The filtrate was then extracted with dichloromethane (3×30 mL) washed with H2O (3×50 mL), brine (50 mL) and dried (Na2SO4). Flash chromatography on silica gel column (4:1 hexane/ethyl acetate to 2:1 hexane/ethyl acetate to 4:1 ethyl acetate/hexane) afforded the intermediate 2-[1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-4-yl]-pyridine as a colorless syrup (20.5 mg, 2.1%). 1H NMR (CDCl3) δ 0.10 (s, 9H), 1.00 (t, 2H, J=7), 3.62 (t, 2H, J=7), 5.40(s, 2H), 7.22(t, 2H, J=4), 7.70–7.85 (m, 2H), 8.10 (d, 1H, J=6),8.65(d, 1H, J=4) ppm; the other isomer shows chemical shift at d 0.10 (s, 9H), 1.00 (t, 2H, J=7), 3.70 (t, 2H, J=7), 5.90(s, 2H), 7.22(t, 2H, J=4), 7.70–7.85 (m, 2H), 8.15 (d, 1H, J=6),8.72(d, 1H, J=4)ppm; LCMS calcd for (C14H21N3OSi): 275.1; found: 276.1 (M+H)+.

1. temperaturethe resultant green suspension was cooled to −78° C
2. additionwas then added through a cannula
3. stirringStirring
4. waitwas continued at −78° C. for 30 minutes
5. waitat room temperature for 10 minutes
6. customThe reaction was quenched with the addition of H2O at 0° C
7. additionThe reaction mixture was diluted with ethyl acetate (80 mL)
8. washwashed successively with H2O (50 mL) and brine (50 mL)
9. dry with materialdried over Na2SO4
10. customAfter removal of the volatile components in vacuo
11. dissolutionthe residue was dissolved in dry DMF (5 mL)
12. stirringwith stirring
13. stirringAfter stirring at room temperature for 15 minutes
14. stirringAfter stirring at room temperature for 3 hours
15. filtrationany undissolved materials were filtered off
16. extractionThe filtrate was then extracted with dichloromethane (3×30 mL)
17. washwashed with H2O (3×50 mL), brine (50 mL)
18. dry with materialdried (Na2SO4)