反应详情

The 5,7-dioxaspiro[2.5]oct-6-ylmethanol (1.7 g, 11.8 mmol) obtained by the step (2b) was mixed with sodium hydride, in oil (708 mg, 17.7 mmol as the content was regarded as 60%) and dimethylsulfoxide (20 ml), and the mixture was stirred at room temperature for 30 minutes. To the reaction mixture, 4-chloro-2,3-dimethylpyridine1-oxide (1.86 g, 11.8 mmol) was added and stirred at 50° C. overnight. After dimethylsulfoxide was distilled off, methanol and NH silica gel were added to the residue and methanol was distilled off. The mixture of the reaction mixture and NH silica gel was purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: ethyl acetate/heptane=1/1 to 4/1→methanol/ethyl acetate=1/9 to 1/4) to obtain the title compound (1.8 g, yield: 57.5%) as a red oil.

1. stirringstirred at 50° C. overnight
2. distillationAfter dimethylsulfoxide was distilled off
3. additionmethanol and NH silica gel were added to the residue and methanol
4. distillationwas distilled off
5. additionThe mixture of the reaction mixture and NH silica gel
6. customwas purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: ethyl acetate/heptane=1/1 to 4/1→methanol/ethyl acetate=1/9 to 1/4)