反应详情

2-Chloro-4-nitro-1H-imidazole (1.08 g, 7.31 mmol), tert-butyl N-methyl-[1-(2-methyloxiran-2-yl-methyl)piperidin-4-yl]carbamate (2.08 g, 7.31 mmol) and sodium acetate (660 mg, 8.04 mmol) in 1-propanol (15 ml) were stirred under reflux overnight. The reaction mixture was concentrated under reduced pressure. The residue was added water, and the mixture was extracted with methylene chloride. The organic phase was dried over sodium sulfate and then filtered. The resulting filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (methylene chloride/methanol=200/1), crystallized from methylene chloride-isopropyl ether to afford tert-butyl N-methyl-[1-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperidin-4-yl]carbamate (348 mg, yield 12%) as a white powder.

1. temperatureunder reflux overnight
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. additionThe residue was added water
4. extractionthe mixture was extracted with methylene chloride
5. dry with materialThe organic phase was dried over sodium sulfate
6. filtrationfiltered
7. concentrationThe resulting filtrate was concentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (methylene chloride/methanol=200/1)
9. customcrystallized from methylene chloride-isopropyl ether