反应详情

66.45 g of 4-phenoxybutylmalonic acid ethyl ester, 45 ml of pyridine, 3 ml of piperidine and 9.9 g of paraformaldehyde are stirred together at 50° C. for 4 hours. After cooling, 400 ml of water are added to the reaction mixture which is then acidified with half-concentrated hydrochloric acid, while cooling with ice. The reaction mixture is then extracted 3 times with 200 ml of diethyl ether each time, the combined organic phases are concentrated and distilled in vacuo. 43.6 g 2-methylene-6-phenoxyhexanoic acid ethyl ester are obtained as a colorless liquid of b.p. 140° C. under 0.06 mm Hg (9 Pa).

1. temperatureAfter cooling
2. temperaturewhile cooling with ice
3. extractionThe reaction mixture is then extracted 3 times with 200 ml of diethyl ether each time
4. concentrationthe combined organic phases are concentrated
5. distillationdistilled in vacuo