反应详情

Under nitrogen atmosphere in a 250 mL round bottomed flask containing 4-bromocinnamic acid (5.0 g, 22 mmoles) in 45 mL of N,N-dimethylformamide (0.5 M) was added benzenesulfonylhydrazide (7.6 g, 44 mmoles). The mixture was stirred at reflux for 12 hours. The solution was cooled at room temperature, aqueous saturated ammonium chloride was added and the aqueous layer was extracted with ethyl acetate 3 times. Combined organic layers were washed with water and brine, dried over anhydrous magnesium sulfate, filtered and concentrated under vacuo. The resulting solid was purified by flash chromatography eluting with 5% methanol:95% dichloromethane to afford 3.66 g (73%) of beige solid.

1. temperatureat reflux for 12 hours
2. extractionthe aqueous layer was extracted with ethyl acetate 3 times
3. washCombined organic layers were washed with water and brine
4. dry with materialdried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated under vacuo
7. customThe resulting solid was purified by flash chromatography
8. washeluting with 5% methanol