Réaction #417931

Équation de réaction

p-Tolyl 3-phenylpropanoate

aluminium chloride

water

→

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

Rendement 34.0%

Solvants

toluene

Conditions de réaction

Traitement

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

Mode opératoire

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