C[Si](C)(C)[N-][Si](C)(C)C.[Li+].[CH2:11]([NH:18][C:19]([C:21]1[S:25][CH:24]=[N:23][C:22]=1[CH3:26])=[O:20])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.[I:27]I>O1CCCC1>[CH2:11]([NH:18][C:19]([C:21]1[S:25][C:24]([I:27])=[N:23][C:22]=1[CH3:26])=[O:20])[C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1A solution of lithium hexamethyldisilazide (4.63 g, 27.65 mmol) in anhydrous tetrahydrofuran (25 mL) was added dropwise to a solution of N-benzyl-4-methylthiazole-5-carboxamide (2.79 g, 12.02 mmol) in anhydrous tetrahydrofuran (25 mL) at −78° C. under nitrogen atmosphere. The reaction mixture was stirred at −78° C. for 1 hour, then iodine (1.68 g, 13.22 mmol) was added in portions. The mixture was stirred at ambient temperature for 90 minutes, quenched with methanol (2 mL) and water (2 mL). The solvent was removed in vacuo and the residue was diluted with water (30 mL) and extracted with dichloromethane (3×40 mL). The organic layers were combined, dried over anhydrous sodium sulphate, filtered and concentrated in vacuo. The residue was purified by column chromatography (20-35% ethyl acetate in hexanes) to afford the title compound as a white solid (2.03 g, 47%): 1H NMR (300 MHz, CDCl3) δ 7.39-7.30 (m, 5H), 6.02 (br s, 1H), 4.57 (d, J=6.0 Hz, 2H), 2.68 (s, 3H); MS (ES+) m/z 359.1 (M+1).
Loading…
