Reaktion #82854

Reaktionsgleichung

sodium hydride

4-methoxyacetophenone

acetophenone

acetic acid

diethyl carbonate

→

desired product

Ethyl 3-(4-methoxyphenyl)-3-oxopropionate

Lösungsmittel

toluene

toluene

toluene

water

toluene

toluene

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturA nitrogen atmosphere was maintained in both
2. 2
   workup.STIRRINGagitated for 5 minutes
3. 3
   Sonstigethe flow of Syltherm (Note 4) in reactor jackets was initiated
4. 4
   Sonstigetemperaturewas reduced to 10° C.
5. 5
   workup.STIRRINGstirring
6. 6
   workup.WAITcontinued for 16 hours
7. 7
   workup.ADDITIONWhen addition
8. 8
   Sonstigethe layers separated
9. 9
   WaschenThe aqueous layer was washed once with 13 L toluene
10. 10
    WaschenThe combined organic layers were washed twice with 6.7 L portions of 7% (w:w) aqueous sodium bicarbonate
11. 11
    WaschenThe toluene solution was washed once with 6.7 L of 23% (w:w) aqueous sodium chloride
12. 12
    TrocknenThe organinc solution was dried over 10 kg sodium sulfate
13. 13
    Filtrationfiltered
14. 14
    Sonstigethe solvent removed on the rotary evaporator

Vorschrift

Simultaneous reactions were run in both a 65-L reactor and a 35-L reactor that share the same reflux system. A nitrogen atmosphere was maintained in both. 4.0 kg (100 moles) of 60% sodium hydride in mineral oil and 32 L toluene were charged into the ambient temperature reactors. The mixture was agitated for 5 minutes and allowed to settle. 20 L of the toluene solution was aspirated. 28 L of toluene was added, agitated for 5 minutes, allowed to settle and 28 L of the toluene solution was aspirated. 68 L of toluene and 8.4 L (69.7 moles) diethyl carbonate were added. The agitation was begun and the flow of Syltherm (Note 4) in reactor jackets was initiated. A solution of 5.0 kg (33.3 moles) 4-methoxyacetophenone in 12 L toluene was added over 20 minutes. When additions were complete, the jacket temperaturewas reduced to 10° C. and stirring continued for 16 hours. A solution of 6.7 L (117 moles) glacial acetic acid in 23 L deionized water was fed at the same rate that was previously used for the acetophenone solution. When addition was complete, agitation was stopped and the layers separated. The aqueous layer was washed once with 13 L toluene. The combined organic layers were washed twice with 6.7 L portions of 7% (w:w) aqueous sodium bicarbonate. The toluene solution was washed once with 6.7 L of 23% (w:w) aqueous sodium chloride. The organinc solution was dried over 10 kg sodium sulfate, filtered, and the solvent removed on the rotary evaporator to provide the desired product.

Quelle