反应详情

0.25 part by weight of piperidine is added dropwise to a mixture of 32.9 parts by weight of ethyl 4-chloroacetoacetate and 9.6 parts by weight of acetaldehyde at -20° C. The mixture is left to stand at -20° C. for 5 to 6 hours and ice-cold 1N hydrochloric acid and ethyl acetate are then added. The ethyl acetate phase is separated off, extracted twice more with 1N hydrochloric acid and then once with water, dried over magnesium sulphate and concentrated. 35.6 parts by weight of a yellow oil are obtained, and are distilled using a bulb tube (oven temperature 80° to 110° C. under 0.07 mm). 15.5 parts by weight of product are obtained.

1. waitThe mixture is left
2. customThe ethyl acetate phase is separated off
3. extractionextracted twice more with 1N hydrochloric acid
4. dry with materialonce with water, dried over magnesium sulphate
5. concentrationconcentrated
6. custom35.6 parts by weight of a yellow oil are obtained
7. distillationare distilled
8. custom(oven temperature 80° to 110° C. under 0.07 mm)
9. custom15.5 parts by weight of product are obtained