反应详情

7.2 g (37.5 mmol) of 5-chloro-6-hydroxynicotinoyl chloride in 10 ml of absolute tetrahydrofuran are added to a boiling solution of 8.55 g (37.5 mmol) of diethyl ethoxymagnesium-malonate (prepared in accordance with Org. Synth. Coll. Vol. IV (1963), 285) in 120 ml of absolute tetrahydrofuran and the mixture is heated under reflux for 2 hours. After neutralization with 2N sulphuric acid, the organic phase is separated off and evaporated. The residue is heated under reflux in a mixture of 30 ml of glacial acetic acid, 20 ml of water and 5 ml of concentrated sulphuric acid for 4 hours. The mixture is stirred into ice-water, brought to pH 4 and extracted with ethyl acetate. Drying and evaporation gives 6 g (93%) of the title compound, melting point: 188° to 189° C.

1. temperaturethe mixture is heated
2. temperatureunder reflux for 2 hours
3. customAfter neutralization with 2N sulphuric acid, the organic phase is separated off
4. customevaporated
5. temperatureThe residue is heated
6. temperatureunder reflux in a mixture of 30 ml of glacial acetic acid, 20 ml of water and 5 ml of concentrated sulphuric acid for 4 hours
7. extractionextracted with ethyl acetate
8. customDrying
9. customevaporation