Reaction #155323

Reaction equation

benzene

3-propoxynaphthalen-2-ylamine

ethyl α-acetyl-4-methoxyphenylacetate

Ethyl acetate

→

2-(4-methoxyphenyl)-3-methyl-5-propoxy-4H-benzo[f]quinolin-1-one

Yield 72.0%

Solvents

n-hexane

Conditions

Workup

1. 1
   workup.ADDITIONwas added 85 mg of Amberlyst 15 (Sigma-Aldrich)
2. 2
   TemperatureThe resulting mixture was heated
3. 3
   Temperatureunder reflux for 20 hours
4. 4
   Filtrationfiltered
5. 5
   Otherto remove resin
6. 6
   Concentrationthe filtrate was concentrated under reduced pressure
7. 7
   workup.ADDITIONDiphenyl ether (2.8 ml) was added to the residue
8. 8
   Temperaturethe mixture was then heated with a mantle heater
9. 9
   Temperatureunder reflux
10. 10
    OtherThe resulting reaction mixture
11. 11
    Temperaturewas cooled to room temperature
12. 12
    Otherdirectly purified
13. 13
    ConcentrationThe purified product was concentrated under reduced pressure
14. 14
    Othergiving an oily substance (800 mg, yield: 72%)
15. 15
    Otherto crystallize
16. 16
    Otherrecrystallized from ethyl acetate

Procedure

To a benzene solution (38 ml) containing 3-propoxynaphthalen-2-ylamine (600 mg, 2.98 mmol) and ethyl α-acetyl-4-methoxyphenylacetate (1.41 g, 5.96 mmol) was added 85 mg of Amberlyst 15 (Sigma-Aldrich). The resulting mixture was heated under reflux for 20 hours using a Dean-Stark trap. The reaction mixture was cooled to room temperature, filtered to remove resin, and then the filtrate was concentrated under reduced pressure. Diphenyl ether (2.8 ml) was added to the residue, and the mixture was then heated with a mantle heater and stirred for 70 minutes under reflux. The resulting reaction mixture was cooled to room temperature, and then directly purified using silica gel column chromatography (dichloromethane:methanol=80:1→70:1). The purified product was concentrated under reduced pressure, giving an oily substance (800 mg, yield: 72%). Ethyl acetate and n-hexane were added to the thus-obtained oily substance to crystallize and then recrystallized from ethyl acetate, giving a pale yellow powder of 2-(4-methoxyphenyl)-3-methyl-5-propoxy-4H-benzo[f]quinolin-1-one (290 mg).

Source