Cyclopropyl methyl ketone → 1-Cyclopropyl-butane-1,3-dione

Participants

Reaction Steps

To a stirred solution of 8.4 g (0.1 mol) of cyclopropyl methyl ketone in 100 mL of ethyl acetate under nitrogen was added dropwise 39 mL (0.1 mol) of a 21 wt % solution of sodium ethoxide in absolute ethanol. The flask was fitted with a condenser and Dean-Stark trap and was heated. The ethanol was removed by azeotropic distillation. Additional ethyl acetate was added to the flask as needed. After three hours the temperature of the distillate had reached 75° C. and the reaction was allowed to cool and stand overnight. The white solid which precipitated out was collected by filtration and the filtrate was set aside. The solid was dissolved in water and this solution was acidified at 0° C. with 10% aqueous hydrochloric acid. This solution was extracted three times with ethyl ether. The ethyl acetate filtrate was washed with water three times, acidified with 10% aqueous hydrochloric acid, and extracted with ethyl ether. The ether extracts from both extractions were combined, dried over magnesium sulfate, and filtered. Removal of solvents gave 3.5 g of 1-cyclopropyl-1,3-butanedione as an oil. Analysis by GC showed 75% purity. This intermediate was used without further purification.

Provenance & Evidence