Reacción #93547

Ecuación de reacción

4-fluoroacetophenone

water

diethyl carbonate

sodium hydride

→

product

Rendimiento 77.4%

Ethyl 3-(4'-fluorophenyl)-3-oxopropanoate

Rendimiento 77.4%

Disolventes

diethyl ether

diethyl ether

pentane

diethyl ether

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrothe pentane is decanted
2. 2
   Secadothe sodium hydride is dried in a stream of nitrogen, 171 g
3. 3
   workup.ADDITIONthe dropwise addition of a solution of 100 g
4. 4
   workup.ADDITIONis added dropwise over a period 1 hour at a rate such that the reaction mixture
5. 5
   workup.STIRRINGthe reaction mixture being stirred under nitrogen throughout
6. 6
   workup.STIRRINGto facilitate stirring
7. 7
   Temperaturathe reaction mixture is refluxed under nitrogen for 3 hours
8. 8
   Otroto destroy the excess sodium hydride) until all solids
9. 9
   workup.DISSOLUTIONdissolve (
10. 10
    workup.ADDITIONthe addition
11. 11
    Otrois separated
12. 12
    Extracciónextracted twice with diethyl ether
13. 13
    Lavadowashed with saturated sodium chloride solution
14. 14
    Secadodried over anhydrous magnesium sulfate
15. 15
    Filtraciónfiltered
16. 16
    Otroevaporated at reduced pressure
17. 17
    Otroto obtain an orange oil
18. 18
    workup.DISTILLATIONThe orange oil is fractionally distilled at about 1 mm. Hg

Procedimiento

57.92 g. (1.448 moles) of 60% sodium hydride/mineral oil is washed twice with pentane, the pentane is decanted, the sodium hydride is dried in a stream of nitrogen, 171 g. (1.448 moles) of diethyl carbonate is added neat at 20°-25° C., and the dropwise addition of a solution of 100 g. (0.724 mole) of 4-fluoroacetophenone in 100 ml of dry diethyl ether is commenced, the reaction mixture being stirred at 20°-25° C. under nitrogen throughout. After about 10% of the diethyl ether solution is added, 10 drops of ethanol is added (gas evolution commences immediately), and the balance of the solution is added dropwise over a period 1 hour at a rate such that the reaction mixture refluxes, the reaction mixture being stirred under nitrogen throughout. 1 kg. of dry diethyl ether is added to facilitate stirring, and the reaction mixture is refluxed under nitrogen for 3 hours and cooled to 0° C., water is carefully added (to destroy the excess sodium hydride) until all solids dissolve (the addition being exothermic), the diethyl ether phase is separated, the aqueous phase is acidified to pH 1 with concentrated hydrochloric acid and extracted twice with diethyl ether, and the three diethyl ether phases are combined, washed with saturated sodium chloride solution, dried over anhydrous magnesium sulfate, filtered and evaporated at reduced pressure to obtain an orange oil. The orange oil is fractionally distilled at about 1 mm. Hg. to obtain the product as a colorless liquid (117.8 g. (77%)). B.p. 117°-125° C.λ1 mm. Hg.

Fuente