反应详情

Under a nitrogen atmosphere, a stirred solution of 10.1 grams (0.045 mole) of 3-bromocinnamic acid and 40 drops of concentrated sulfuric acid in 75 mL of ethanol was heated at reflux for about 19 hours. After this time the reaction mixture was concentrated under reduced pressure to a residual oil. The oil was dissolved in methylene chloride, and the solution was washed with 50 mL of water and then with 50 mL of an aqueous solution saturated with sodium bicarbonate. The organic layer was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure, yielding about 11.4 grams of ethyl 3-(3-bromophenyl)-2-propenoate. The NMR spectrum was consistent with the proposed structure.

1. temperatureat reflux for about 19 hours
2. concentrationAfter this time the reaction mixture was concentrated under reduced pressure to a residual oil
3. dissolutionThe oil was dissolved in methylene chloride
4. washthe solution was washed with 50 mL of water
5. dry with materialThe organic layer was dried with magnesium sulfate
6. filtrationfiltered
7. concentrationThe filtrate was concentrated under reduced pressure