反应详情

A mixture of 5-(dimethylamino)-2-[(dimethylamino)methylene]-3-oxopent-4-enenitrile (64.3 g, 333 mmol) and ammonium acetate (126 g, 1.66 mol) in EtOH (1.8 L) was heated at reflux for 60 h and concentrated to remove solvent. The resultant semi-solid residue was diluted with EtOAc, filtered and washed with EtOAc followed by CH2Cl2. The filtrate was evaporated to a reduced volume. The precipitated solids were collected by filtration, washed with EtOAc and a minimum amount of EtOH. The process of evaporation and crystallization was repeated to obtain more solid product from the mother liquor. The combined off-white solids provided 20.9 g of 4-hydroxynicotinonitrile (53%); melting range: 234-236° C.

1. temperaturewas heated
2. temperatureat reflux for 60 h
3. concentrationconcentrated
4. customto remove solvent
5. additionThe resultant semi-solid residue was diluted with EtOAc
6. filtrationfiltered
7. washwashed with EtOAc
8. customThe filtrate was evaporated to a reduced volume
9. filtrationThe precipitated solids were collected by filtration
10. washwashed with EtOAc
11. customThe process of evaporation and crystallization
12. customto obtain more solid product from the mother liquor