Reaktion #417931

Reaktionsgleichung

p-Tolyl 3-phenylpropanoate

aluminium chloride

water

→

1-(2-hydroxy-5-methylphenyl)-3-phenylpropan-1-one

Ausbeute 34.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was heated
2. 2
   TemperaturHeating
3. 3
   Sonstigewas removed
4. 4
   workup.ADDITIONtoluene was added (30 ml)
5. 5
   workup.STIRRINGStirring
6. 6
   workup.WAITwas continued for 15 min
7. 7
   Sonstigeto obtain a brown solution, which
8. 8
   Temperaturwas cooled with an ice bath
9. 9
   workup.STIRRINGThe resulting biphasic mixture was further stirred until it
10. 10
    Sonstigereached room temperature
11. 11
    WaschenThe organic layer was washed 3 times with water
12. 12
    Waschenby washing three times with half saturated aq. NaCl
13. 13
    Trocknendried over MgSO4
14. 14
    Einengenconcentrated in a rotary evaporator
15. 15
    Sonstigeto obtain 9.44 g (73%) of crude brown oil, which
16. 16
    workup.DISTILLATIONwas short-path distilled at 129° C./0.05 mbar

Vorschrift

p-Tolyl 3-phenylpropanoate (13.0 g, 54.1 mmol) was added to aluminium chloride (9.38 g, 70.3 mmol) and the mixture was heated under stirring to 178° C. for 2 h. Heating was removed and toluene was added (30 ml). Stirring was continued for 15 min to obtain a brown solution, which was cooled with an ice bath prior to the careful, dropwise addition of water (30 ml). The resulting biphasic mixture was further stirred until it reached room temperature, then diluted with toluene. The organic layer was washed 3 times with water, then twice with 1N aq. NaOH solution (50 ml). The organic layer was then neutralized by washing three times with half saturated aq. NaCl, then dried over MgSO4 and concentrated in a rotary evaporator to obtain 9.44 g (73%) of crude brown oil, which was short-path distilled at 129° C./0.05 mbar to obtain 1-(2-hydroxy-5-methylphenyl)-3-phenylpropan-1-one (4.39 g, 34%). The product was further purified by column flash chromatography on silica to obtain 3.68 g (28%) of product, which was finally recrystallized from hexane to yield 2.93 g (25%) of product as white crystals, melting point 40.3° C.

Quelle