Reaktion #78380

Reaktionsgleichung

tin tetrachloride

methyl isobutyrylacetate

4-fluorobenzonitrile

toluene

→

methyl 2-[1-amino-1-(4-fluorophenyl)-methylene]-4-methyl-3-oxopentanoate

Ausbeute 75.2%

Lösungsmittel

n-hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITAfter half an hour at room temperature
2. 2
   workup.DISTILLATION3 h, 175 ml of toluene were distilled off at normal pressure
3. 3
   Temperaturthe mixture was cooled to room temperature
4. 4
   workup.ADDITIONtreated with 450 ml of saturated sodium carbonate and 300 ml of ethyl acetate
5. 5
   SonstigeThe organic phase was separated off
6. 6
   Extraktionthe aqueous phase (after dilution with 300 ml of water) was again extracted with 300 ml of ethyl acetate
7. 7
   TrocknenAfter drying the combined organic phases over sodium sulphate
8. 8
   Sonstigethe solvent was removed in vacuo (40° C./25 mbar)
9. 9
   Sonstige127.2 g of crude product were obtained in the form of a slightly yellowish solid, which
10. 10
    FiltrationAfter hot filtration
11. 11
    Temperatursubsequent cooling in an ice bath

Vorschrift

75.09 g of methyl isobutyrylacetate (0.50 mol, concentration 96%) and 61.80 g of 4-fluorobenzonitrile (0.50 mol, concentration 98%) were introduced into [500 ml of toluene and treated with 144.7 g of tin tetrachloride (0.55 mol, concentration 99%) at room temperature over the course of 16 min. After half an hour at room temperature, the thick suspension was heated to 80° C. After. 3 h, 175 ml of toluene were distilled off at normal pressure, and the mixture was cooled to room temperature and treated with 450 ml of saturated sodium carbonate and 300 ml of ethyl acetate. The organic phase was separated off and the aqueous phase (after dilution with 300 ml of water) was again extracted with 300 ml of ethyl acetate. After drying the combined organic phases over sodium sulphate, the solvent was removed in vacuo (40° C./25 mbar). 127.2 g of crude product were obtained in the form of a slightly yellowish solid, which was dissolved in 160 ml of n-hexane (slightly turbid solution). After hot filtration and subsequent cooling in an ice bath, 99.8 g of methyl 2-[1-amino-1-(4-fluorophenyl)-methylene]-4-methyl-3-oxopentanoate were obtained after filtration in the form of a pale yellow solid.

Quelle