Potassium Hydroxide → 4-Methyl-7-(3-thienyl)-5,6,7,8-tetrahydroquinolin-5-one

Temperature

115 °C

In a mixture of ethanol (200 ml) and toluene (600 ml) was dissolved 1-amino-5-(3-thienyl)cyclohexen-3-one (10 g), and to the solution were added 3-oxobutylaldehydedimethylacetal (17.4 g) and granulated potassium hydroxide (2.87 g). The mixture was stirred at 115° C. (bath temperature), and to the reaction solution were added granulated potassium hydroxide (590 mg), 30 minutes later; 1 hour later; and 1.5 hours later; respectively. The reaction solution was stirred at the same temperature for 1 hour and cooled. Under reduced pressure, the solvent was evaporated, and to the residue were added ethyl acetate (250 ml) and water (70 ml). The mixture was shaken, and the separated ethyl acetate layer was washed with water (40 ml, thrice) and concentrated under reduced pressure. The residue was purified with silica gel column chromatography (EtOAc/hexane) and eluted with ethyl acetate/hexane to give 4-methyl-7-(3-thienyl)-5,6,7,8-tetrahydroquinolin-5-one (6.5 g) as pale yellow crystals.

1. custom1 hour
2. custom1.5 hours
3. stirringThe reaction solution was stirred at the same temperature for 1 hour
4. temperaturecooled
5. customUnder reduced pressure, the solvent was evaporated
6. additionto the residue were added ethyl acetate (250 ml) and water (70 ml)
7. stirringThe mixture was shaken
8. washthe separated ethyl acetate layer was washed with water (40 ml, thrice)
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified with silica gel column chromatography (EtOAc/hexane)
11. washeluted with ethyl acetate/hexane

ORD record

ord-dd323e2946c4496a963235ce54882405

Source dataset

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06350749B1