反应详情

To 4-cyano-2-hydroxymethylpyridine (1.1 g, 8.2 mmol) from stage A in dry DMSO (18 mL) was added N,N-dicyclohexylcarbodiimide (5.08 g, 24.6 mmol) and phosphoric acid (0.4 g, 4.1 mmol). The mixture was stirred overnight at room temperature. The solid was removed by filtration and washed with ether and water. The filtrate and washings were combined, and the organic layer separated. The aqueous layer was further extracted 4 times with ether, the organics combined, dried over magnesium sulphate and evaporated. The residue was purified by SPE silica column chromatography, eluting with dichloromethane, then chloroform, then diethyl ether. Evaporation of the appropriate fractions afforded 4-cyanopyridine-2-carboxaldehyde as a solid.

1. customThe solid was removed by filtration
2. washwashed with ether and water
3. customthe organic layer separated
4. extractionThe aqueous layer was further extracted 4 times with ether
5. dry with materialdried over magnesium sulphate
6. customevaporated
7. customThe residue was purified by SPE silica column chromatography
8. washeluting with dichloromethane
9. customEvaporation of the appropriate fractions