反应详情

Sodium hydride (3.9 g) was suspended in dimethyl sulfoxide (24 mL), and diethyl methyl malonate (16 mL) was added at 0° C., and then the reaction mixture was stirred at room temperature for 1.5 hours. The reaction mixture was heated to 100° C., and a solution of 2,5-dibromonitrobenzene (15.3 g) in dimethyl sulfoxide (17 mL) was added at 100° C., and then the reaction mixture was stirred at 100° C. for 5 hours. The reaction mixture was quenched with water, and extracted with ethyl acetate. The obtained organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The residue was dissolved in ethanol (75 mL), and tin (11.5 g) was added at room temperature. Concentrated hydrochloric acid (45 mL) was added at 0° C., and then the reaction mixture was heated at reflux for 2 hours. After cooling to room temperature, the reaction mixture was quenched with water, and extracted with ethyl acetate. The obtained organic layer was washed with a saturated aqueous solution of sodium hydrogen carbonate and brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography to give the titled compound (4.9 g) as a brown solid.

1. temperatureThe reaction mixture was heated to 100° C.
2. stirringthe reaction mixture was stirred at 100° C. for 5 hours
3. customThe reaction mixture was quenched with water
4. extractionextracted with ethyl acetate
5. washThe obtained organic layer was washed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationthe filtrate was concentrated under reduced pressure
9. dissolutionThe residue was dissolved in ethanol (75 mL)
10. additiontin (11.5 g) was added at room temperature
11. additionConcentrated hydrochloric acid (45 mL) was added at 0° C.
12. temperaturethe reaction mixture was heated
13. temperatureat reflux for 2 hours
14. temperatureAfter cooling to room temperature
15. customthe reaction mixture was quenched with water
16. extractionextracted with ethyl acetate
17. washThe obtained organic layer was washed with a saturated aqueous solution of sodium hydrogen carbonate and brine
18. dry with materialdried over anhydrous sodium sulfate
19. filtrationfiltered
20. concentrationthe filtrate was concentrated under reduced pressure
21. customThe obtained residue was purified by silica gel column chromatography