反应详情

3-(4-Trifluoromethylphenyl)-2-propenyl (S)-4-[3-(2-bromo-4-nitroimidazol-1-yl)-2-hydroxy-2-methylpropyl]piperazine-1-carboxylate (3.5 g, 6.07 mmol) was dissolved in N,N′-dimethylformamide (10.5 ml), and sodium hydride (316 mg, 7.89 mmol) was added while cooling on ice followed by stirring at the same temperature for 1.5 hours. To the reaction solution, ethyl acetate (3.5 ml) and water (24.5 ml) were added followed by stirring for 30 minutes. The precipitated crystals were filtered off, washed with water, and purified by silica gel column chromatography (ethyl acetate). Recrystallization from 2-propanol/water gives a light yellow powder of 3-(4-trifluoromethylphenyl)-2-propenyl (S)-4-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazine-1-carboxylate (2.07 g, 69%).

1. temperaturewhile cooling on ice
2. stirringby stirring for 30 minutes
3. filtrationThe precipitated crystals were filtered off
4. washwashed with water
5. custompurified by silica gel column chromatography (ethyl acetate)
6. customRecrystallization from 2-propanol/water