反应详情

The (5,5-dimethyl-1,3-dioxan-2-yl)methanol (2 g, 13.7 mmol) obtained in the step (1b) was mixed with sodium hydride in oil (822 mg, 20.6 mmol as the content was regarded as 60%) and dimethylsulfoxide (20 ml). The mixture was stirred at room temperature for 30 minutes. To the reaction mixture, 4-chloro-2,3-dimethylpyridine1-oxide (2.16 g, 13.7 mmol) was added and stirred at 50° C. overnight, and further allowed to stand still for one day at room temperature. After dimethylsulfoxide was distilled off, methanol and NH silica gel were added to the residue and then 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 obtain the title compound (3.1 g, yield: 84.6%) as a light yellow oil.

1. stirringstirred at 50° C. overnight
2. waitto stand still for one day at room temperature
3. distillationAfter dimethylsulfoxide was distilled off
4. additionmethanol and NH silica gel were added to the residue
5. distillationmethanol was distilled off
6. additionThe mixture of the reaction mixture and NH silica gel
7. 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)