反应详情

A modification of the general method described in Part B of Example 3 was followed. mCPBA (60% pure, 1.39 g, 47.3 mmol) was added in portions to a solution of 8-benzyloxy-2-ethyl-1-methyl-1H-imidazo[4,5-c]quinoline (1.5 g, 47 mmol) in chloroform (75 mL), and the reaction was stirred for 5.5 hours. During the work-up, the combined aqueous washings were extracted with dichloromethane, and the product precipitated from solution. The combined dichloromethane and chloroform solutions were concentrated under reduced pressure until crystals formed and then allowed to stand overnight. The crystals were isolated by filtration. The aqueous solution was extracted with chloroform, and the combined extracts were washed with water (2×) and concentrated under reduced pressure to a small volume. Hexanes were added, and the resulting crystals were isolated by filtration. The mother liquor was concentrated under reduced pressure to afford a solid that was recrystallized from 2-propanol. The three batches of crystals were combined to yield 1.30 g of 8-benzyloxy-2-ethyl-1-methyl-5-oxido-1H-imidazo[4,5-c]quinoline.

1. extractionDuring the work-up, the combined aqueous washings were extracted with dichloromethane
2. customthe product precipitated from solution
3. concentrationThe combined dichloromethane and chloroform solutions were concentrated under reduced pressure until crystals
4. customformed
5. waitto stand overnight
6. customThe crystals were isolated by filtration
7. extractionThe aqueous solution was extracted with chloroform
8. washthe combined extracts were washed with water (2×)
9. concentrationconcentrated under reduced pressure to a small volume
10. additionHexanes were added
11. customthe resulting crystals were isolated by filtration
12. concentrationThe mother liquor was concentrated under reduced pressure
13. customto afford a solid
14. customthat was recrystallized from 2-propanol