反应详情

To a dimethylsulfoxide (15 ml) solution of the (8-methyl-1,4,7,9-tetraoxaspiro[4.5]dec-8-yl)methanol (1.11 g, 5.82 mmol) obtained in the step (5c), sodium hydride, in oil (326 mg, 8.15 mmol as the content was regarded as 60%) was added at room temperature in a nitrogen atmosphere. The mixture was stirred for 30 minutes in the same conditions. To the reaction mixture, 4-chloro-2,3-dimethylpyridine 1-oxide (917 mg, 5.82 mmol) was added at room temperature and the reaction mixture was stirred at 70° C. for 4.5 hours. The reaction mixture was concentrated and the residue was purified by silica gel column chromatography (elution solvent: ethyl acetate/methanol=1/0-5/2 gradient) and desired fractions were concentrated to obtain the title compound (1.20 g, 66.1% yield) as a brown oil.

1. additionwas added at room temperature in a nitrogen atmosphere
2. stirringthe reaction mixture was stirred at 70° C. for 4.5 hours
3. concentrationThe reaction mixture was concentrated
4. customthe residue was purified by silica gel column chromatography (elution solvent: ethyl acetate/methanol=1/0-5/2 gradient)
5. concentrationdesired fractions were concentrated