反应详情

温度

-78 °C

1.6 M n-BuLi (12.0 mL, 19.2 mmol) is slowly added to a solution of 1-ethoxymethyl-1H-imidazole [available via the procedure outlined in Tang, C. C.; Davalian, D.; Huang, P.; Breslow, R. J. Am. Chem. Soc. 1978, 100, 3918] (2.20 g, 17.4 mmol) in THF (30 mL) at −78° C. under N2. The reaction mixture is stirred at −78° C. for 20 minutes whereupon tributyl tin chloride (5.7 mL, 20.9 mmol) is added slowly. The reaction mixture is stirred at −78° C. for 10 minutes and then warmed to room temperature. After stirring at room temperature for 1.5 hours, the reaction mixture is concentrated in vacuo. The residue is triturated with hexanes and filtered, and the filtrate is concentrated in vacuo. The residue is again triturated with hexanes and filtered, and the filtrate concentrated in vacuo. The 1H NMR of the resulting oil indicates a 2:1 mixture of 1-ethoxymethyl-2-tributylstannanyl-1H-imidazole: 1-ethoxymethyl-1H-imidazole. This material is used in the next reaction (Example 5) without further purification. Selected 1H NMR resonances (400 MHz, CDCl3) δ 7.21 (s, 1H), 7.14 (s, 1H), 5.24 (s, 2H) ppm.

1. customat −78° C.
2. additionis added slowly
3. temperaturewarmed to room temperature
4. stirringAfter stirring at room temperature for 1.5 hours
5. concentrationthe reaction mixture is concentrated in vacuo
6. customThe residue is triturated with hexanes
7. filtrationfiltered
8. concentrationthe filtrate is concentrated in vacuo
9. customThe residue is again triturated with hexanes
10. filtrationfiltered
11. concentrationthe filtrate concentrated in vacuo
12. additiona 2:1 mixture of 1-ethoxymethyl-2-tributylstannanyl-1H-imidazole
13. customThis material is used in the next reaction (Example 5) without further purification