反应详情

A mixture of 2-chloro-5,6-dimethyl-3-pyridinecarboxaldehyde (16.85 g), malonic acid (11.45 g) piperidine (10 ml) and pyridine (100 ml) was heated under reflux for 1 hour and evaported to an oil. This oil was dissolved in sodium hydroxide solution and was extracted with chloroform (discarded). The aqueous phase was acidified with hydrochloric acid and was extracted with chloroform. The chloroform extracts were washed with water and evaporated to give 3-(2-chloro-5,6-dimethyl-3-pyridyl)acrylic acid (18.3 g, 87%) m.p. 150°-158°. This acid was esterified using ethanol and sulphuric acid to give the ethyl ester m.p. 85°-88°.

1. temperaturewas heated
2. temperatureunder reflux for 1 hour
3. extractionwas extracted with chloroform (discarded)
4. extractionwas extracted with chloroform
5. washThe chloroform extracts were washed with water
6. customevaporated