Synthesis and Reactions of 4,4-DIMETHYL-2-CYCLOHEXEN-1-ONE Synthesis

4 4-dimethyl-2-cyclohexen-1-one is a ketone organic compound used in organic synthesis and scientific research experiments.

Basic information

CAS:1073-13-8

IUPAC Standard InChI: InChI=1S/C8H12O/c1-8(2)5-3-7(9)4-6-8/h3,5H,4,6H2,1-2H3

IUPAC Standard InChIKey: HAUNPYVLVAIUOO-UHFFFAOYSA-N

Individual Reactions

By formula: C8H11O- + H+ = C8H12O

Synthesis

A dry, 1-l three-necked flask is equipped with a mechanical stirrer, a pressure-equalizing dropping funnel, a nitrogen inlet tube, and an ice-water cooling bath. The apparatus is flushed with nitrogen, and a static nitrogen atmosphere is maintained in the reaction vessel throughout the reaction.

1-(2-Methylpropenyl)pyrrolidine (62.6 g., 0.501 mole) is added to the reaction flask before 42.1 g. (0.601 mole) of methyl vinyl ketone is added, dropwise with stirring and cooling, over 5 minutes. After the resulting mixture has been stirred with cooling for 10 minutes, the ice bath is removed and stirring at room temperature is continued for 4 hours. The reaction mixture is again cooled with an ice-water bath, and 250 ml. of 8 M hydrochloric acid is added, dropwise and with stirring. After addition is complete, the mixture is stirred with cooling for 10 minutes, then stirred at room temperature for 14 hours.

The resulting brown reaction mixture is extracted with two 300-ml. portions of diethyl ether. The residual aqueous phase is neutralized by the cautious addition of 150–155 g of solid sodium hydrogen carbonate and extracted with two 400-ml. portions of ether. The combined ethereal extracts are dried over anhydrous sodium sulfate and concentrated with a rotary evaporator. The residual liquid is distilled under reduced pressure, yielding 44.2–53.0 g (71–85%) of 4,4-dimethyl-2-cyclohexen-1-one as a colorless liquid, b.p. 73–74° (14 mm.), n25D 1.4699–1.4726.