[Li]CCCC.[CH2:6]([O:8][CH2:9][N:10]1[CH:14]=[CH:13][N:12]=[CH:11]1)[CH3:7].[CH2:15]([Sn:19](Cl)([CH2:24][CH2:25][CH2:26][CH3:27])[CH2:20][CH2:21][CH2:22][CH3:23])[CH2:16][CH2:17][CH3:18]>C1COCC1>[CH2:6]([O:8][CH2:9][N:10]1[CH:14]=[CH:13][N:12]=[C:11]1[Sn:19]([CH2:20][CH2:21][CH2:22][CH3:23])([CH2:24][CH2:25][CH2:26][CH3:27])[CH2:15][CH2:16][CH2:17][CH3:18])[CH3:7]1.6 M n-BuLi (12.0 mL, 19.2 mmol) is slowly added to a solution of 1-ethoxymethyl-1H-imidazole (2.20 g, 17.4 mmol; prepared essentially as described by Tang, et al. (1978) J. Am. Chem. Soc. 100:3918) in THF (30 mL) at −78° C. under N2. The reaction mixture is stirred at −78° C. for 20 minutes, whereupon tributyltin chloride (5.7 mL, 20.9 mmol) is slowly added. 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 without further purification. Selected 1H NMR resonances (400 MHz, CDCl3) δ 7.21 (s, 1H), 7.14 (s, 1H), 5.24 (s, 2H) ppm.
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