Acetyl chloride → 6-Acetyl-1,4,4-trimethyl-3,4-dihydroquinolin-2(1H)-one

Participants

Reaction Steps

21.5 g of 3,4-dihydro-1,4,4-trimethyl-2(1H)-quinolinone were dissolved in 43 g of carbon disulphide and the solution was treated with 85 g of aluminum chloride. 17.8 g of acetyl chloride were slowly added dropwise thereto while cooling with ice and stirring vigorously. The mixture was subsequently heated at reflux for 1.5 hours, cooled and treated cautiously with ice-water. The resulting mixture was extracted three times with ethyl acetate and the ethyl acetate extracts were washed with water, dried and evaporated. The thus-obtained brownish oil was filtered over silica gel [eluting agent: hexane/ethyl acetate (2:1)] and then recrystallized from hexane/ethyl acetate. There were obtained 19.5 g of 6-acetyl-3,4-dihydro-1,4,4-trimethyl-2(1H)-quinolinone in the form of colourless crystals of melting point 75°-77° C.

Provenance & Evidence