Phenetole → Cyclopropyl 4-ethoxyphenyl ketone

Participants

Reaction Conditions

Reaction Steps

Under an argon atmosphere a stirred suspension of 36.7 grams (0.275 mole) of aluminum chloride in 225 mL of carbon disulfide was cooled to 0° C., and 22.7 mL (0.25 mole) of cyclopropanecarboxylic acid chloride was added dropwise during a 15 minute period. During the addition and for 30 minutes after its completion the reaction mixture temperature was maintained at 0°-15° C. Then 34.8 mL of ethoxybenzene was added dropwise during a one hour period. The reaction mixture temperature was maintained at 5°-10° C. during this addition. Upon completion of addition, the reaction mixture was allowed to warm to ambient temperature as it stirred for one hour. Petroleum ether, 250 mL, was added to the reaction mixture, and the suspension was stirred for ten minutes. The solid was collected by filtration and washed with petroleum ether. The solid was returned to the reaction vessel and, with stirring, was cooled to 0°-10° C. while 50 mL of water was added dropwise during a 30 minute period. Upon completion of addition, the mixture was stirred until the evolution of hydrogen chloride ceased. An additional 250 mL of water was then added, and the mixture was stirred at ambient temperature for 30 minutes. It was then warmed to 80° C. where it stirred for an additional 30 minutes. The mixture was cooled, and a solid was collected by filtration. The solid was dissolved in methylene chloride, and the solution was dried with sodium sulfate. The mixture was filtered, and the filtrate was concentrated under reduced pressure to a residual solid. The solid was recrystallized from heptane, yielding, in two crops, 44.0 grams of cyclopropyl (4-ethoxyphenyl) ketone, m.p. 67°-70° C. The nmr spectrum was consistent with the proposed structure.

Provenance & Evidence