Reaction #417931

Reaction equation

p-Tolyl 3-phenylpropanoate

aluminium chloride

water

→

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

Yield 34.0%

Solvents

toluene

Conditions

Workup

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

Procedure

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.

Source