反应详情

Methyl 3-methylbenzoate (45.0 g), N-bromosuccinimide (53.4 g) and a catalitic amount of azobisisobutyronitrile were refluxed in carbon tetrachloride (500 ml) with stirring for 24 hours. The reaction mixture was filtered and the filtrate was concentrated under a vacuum. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=20:1), thereby yielding an oil. The oil was dissolved in dimethylformamide (1.5 l) and the mixture, with piperidine (63.2 g) and potassium carbonate (205 g) added thereto, was stirred all day and night at room temperature. The reaction mixture, with water added thereto, was extracted with ethyl acetate. The extract was dried over sodium sulfate anhydride, and then concentrated under a vacuum. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1), thereby yielding an oil. Potassium hydroxide (78.0 g), water (325 ml), and ethanol (325 ml) were added to the oil and the mixture was refluxed with stirring for 2 hours. After being neutralized with acetic acid, the reaction mixture, with chloroform added thereto, was filtered. The filtrate was concentrated under a vacuum. The resulting solid was washed with ethanol, thereby yielding 24.4 g of the aimed compound. The resulting solid was washed with ethanol, thereby yielding 24.4 g of the aimed compound.

1. filtrationThe reaction mixture was filtered
2. concentrationthe filtrate was concentrated under a vacuum
3. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=20:1)
4. customyielding an oil
5. stirringwas stirred all day and night at room temperature
6. extractionwas extracted with ethyl acetate
7. dry with materialThe extract was dried over sodium sulfate anhydride
8. concentrationconcentrated under a vacuum
9. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1)
10. customyielding an oil
11. temperaturethe mixture was refluxed
12. stirringwith stirring for 2 hours
13. filtrationwas filtered
14. concentrationThe filtrate was concentrated under a vacuum
15. washThe resulting solid was washed with ethanol