反应详情

An eggplant flask was charged with 5-(benzothiazol-2-yl)-2-hydroxymethyl-1-(tetrahydropyran-4-yl)benzimidazole (see Working Example 8) (0.431 g, 1.179 mmol), oxalyl chloride (0.178 g, 1.40 mmol), and anhydrous dichloromethane (22 mL), and after the addition of anhydrous N,N-dimethylformamide (5 drops) at room temperature, this was refluxed for 3.5 hours. After cooling to room temperature, the solvent was distilled off under reduced pressure. To the yellow residue was added anhydrous tetrahydrofuran (1 mL) and anhydrous sodium iodide (0.267 g, 1.78 mmol), followed by a tetrahydrofuran solution of dimethylamine (2.0 M, 5 mL), and this was refluxed for 16 hours. After being allowed to cool to room temperature, the solvent was distilled off under reduced pressure. An adsorbed silica gel powder was prepared from the yellow residue (0.8 g) using chloroform (approx. 30 mL) and silica gel (3.2 g), and this was purified by silica gel column chromatography (silica gel: 32 g, MeOH/CHCl3=1/20) to yield the title compound (0.176 g, 38.0% yield) as a pale yellow powder.

1. temperaturethis was refluxed for 3.5 hours
2. distillationthe solvent was distilled off under reduced pressure
3. temperaturethis was refluxed for 16 hours
4. temperatureto cool to room temperature
5. distillationthe solvent was distilled off under reduced pressure
6. customAn adsorbed silica gel powder was prepared from the yellow residue (0.8 g)
7. customthis was purified by silica gel column chromatography (silica gel: 32 g, MeOH/CHCl3=1/20)