反应详情

Dissolve crude 6-(1-ethoxy-vinyl)-nicotinonitrile (14.5 g, ca. 80%) in THF (120 mL) and 2.5 N hydrochloric acid (40 mL). Stir the solution for 16 h at room temperature. Quench the reaction with saturated aqueous NaHCO3 (pH to 7.5). Extract the mixture with EtOAc (200 mL). Dry the organic layer over Na2SO4, filter and concentrate in vacuo. Purify the crude mixture by chromatography on silica gel (120 g) eluting with hexane/EtOAc (9:1 to 3:1 gradient) to obtain the desired intermediate (4.2 g, 65%).

1. customQuench
2. customthe reaction with saturated aqueous NaHCO3 (pH to 7.5)
3. extractionExtract the mixture with EtOAc (200 mL)
4. dry with materialDry the organic layer over Na2SO4
5. filtrationfilter
6. concentrationconcentrate in vacuo
7. customPurify the crude mixture by chromatography on silica gel (120 g)
8. washeluting with hexane/EtOAc (9:1 to 3:1 gradient)