反应详情

Ethyl 3-amino-4-cyclohexylaminobenzoate (500 mg) obtained in Example 1, Step 3, was dissolved in methyl alcohol (6 ml) and trans-4-stilbenecarbaldehyde (397 mg) was added under ice-cooling. The mixture was stirred overnight at room temperature. The reaction mixture was ice-cooled and benzofuroxan (259 mg) dissolved in acetonitrile (2 ml) was added. The mixture was stirred for 7 hr at 50° C., The reaction mixture was ice-cooled. After 1N sodium-hydroxide was added, ethyl acetate was added and the mixture was extracted. The organic layer was washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography (developing solvent, n-hexane:ethyl acetate=4:1) to give the title compound (540 mg, yield 63%).

1. temperaturecooling
2. temperaturecooled
3. additionwas added
4. stirringThe mixture was stirred for 7 hr at 50° C.
5. temperaturecooled
6. additionAfter 1N sodium-hydroxide was added
7. extractionthe mixture was extracted
8. washThe organic layer was washed with water and saturated brine
9. dry with materialdried over anhydrous magnesium sulfate
10. concentrationconcentrated under reduced pressure
11. customThe residue was purified by silica gel flash chromatography (developing solvent, n-hexane:ethyl acetate=4:1)