Water → ethyl 3-chlorobut-2-enoate

Participants

Reaction Conditions

Reaction Steps

In a reaction vessel flushed with argon gas was placed 437.4 grams (3.36 moles) of ethyl acetoacetate in 500 ml of methylene chloride. The stirred solution was cooled to 0° C. and 700 grams (3.36 moles) of phosphorous pentachloride was added in portions at a rate such that the reaction mixture temperature did not exceed 5°. Upon completion of addition, the reaction mixture was stirred at 0°-5° for 16 hours. Five-hundred ml of water was added dropwise, and the layers in the resultant two-phase system were separated. The water layer was made alkaline with solid sodium bicarbonate and extracted with several 100-ml portions of methylene chloride. The organic layer from the reaction mixture was washed with water until all the solid material in it dissolved. The washed organic layer and the methylene chloride washings of the water layer were combined and dried with sodium sulfate. The mixture was filtered and the filtrate concentrated under reduced pressure to a residual oil. The oil was first distilled under reduced pressure using a Vigreux column. Fractions boiling at 52°-65°/0.40-1.07×103Pa were combined and subjected to a second distillation under reduced pressure using a spinning band distilling system. Fractions boiling at 66°-70°/0.40-1.07×103Pa from the first distillation and fractions boiling at 66.5°-82°/1.20×103Pa from the second distillation were subjected to a third distillation under reduced pressure using a spinning band distilling system. The fraction, bp 46°/1.33×103Pa from the second distillation was combined with the fractions, bp 42°-45°/1.20×103Pa from the third distillation to give 38.4 grams of ethyl [E]-3-chloro-2-butenoate.

Provenance & Evidence