Ammonium Acetate → 1-Amino-5-(5-chloro-2-methoxyphenyl)cyclohexen-3-one

Participants

Reaction Steps

A solution of 5-(5-chloro-2-methoxyphenyl)cyclohexane-1,3-dione (5.0 g) and ammonium acetate (4.6 g) in ethanol (100 ml) was refluxed for 20 hours. Under reduced pressure, the solvent was evaporated, and the residue was dissolved in ethyl acetate. The solution was washed with water and saturated brine, and dried with magnesium sulfate. Under reduced pressure, the solvent was evaporated to give 1-amino-5-(5-chloro-2-methoxyphenyl)cyclohexen-3-one, which was dissolved in ethanol (120 ml) and toluene (210 ml). To the solution were added 3-oxobutylaldehydedimethylacetal (6.5 g) and powdery potassium hydroxide (0.92 g), and the mixture was refluxed. To the mixture was added powdery potassium hydroxide (0.19 g), 30 minutes later; were added powdery potassium hydroxide (0.19 g) and 3-oxobutylaldehydedimethylacetal (0.52 g), 1 hour later; and was added powdery potassium hydroxide (0.19 g), 1.5 hours later, and the mixture was stirred at the same temperature for 2 hours and cooled. Under reduced pressure, the solvent was evaporated, and to the residue was added ethyl acetate. The organic layer was washed with water and saturated brine, and dried with magnesium sulfate. Under reduced pressure, ethyl acetate was evaporated, and the residue was purified with silica gel column (ethyl acetate-hexane) to give 7-(5-chloro-2-methoxyphenyl)-4-methyl-5,6,7,8-tetrahydroquinolin-5-one (2.2 g) as colorless crystals.

Provenance & Evidence