反应详情

Lithium aluminum hydride, 3.8 g. (0.1 mole), is wegihed under nitrogen, transferred to a dry, nitrogen-flushed reaction flask, and suspended in 300 ml. of absolute ether. The mixture is stirred at reflux for 30 minutes and then, after cooling to room temperature, a solution of 36.16 g. (0.108 mole) of ethyl 2-(4-bromophenethyl)-benzoate in 100 ml. of absolute ether is added dropwise. The mixture is stirred at room temperature overnight. The excess lithium aluminum hydride is decomposed by the addition of 5 ml. of ethyl acetate and the mixture then is hydrolyzed by the addition of 30 ml. of saturated ammonium chloride solution. The ethereal layer is separated and the aqueous layer re-extracted with ether. Evaporation of the combined, washed, and dried ethereal extracts under reduced pressure leaves the product as the residual solid, m.p. 72°-75.5° C. Recrystallization from hexane-cyclohexane affords purified material, m.p. 74°-75.5° C. A sample for analysis melts at 75°-76.5° C. after recrystallization from hexane.

1. customflushed
2. customreaction flask
3. temperatureat reflux for 30 minutes
4. stirringThe mixture is stirred at room temperature overnight
5. customThe ethereal layer is separated
6. extractionthe aqueous layer re-extracted with ether
7. customEvaporation of the
8. washwashed
9. customdried ethereal extracts under reduced pressure
10. customleaves the product as the residual solid, m.p. 72°-75.5° C
11. customRecrystallization from hexane-cyclohexane
12. customaffords
13. custompurified material, m.p. 74°-75.5° C
14. customA sample for analysis melts at 75°-76.5° C. after recrystallization from hexane