Pyridine → 6-Oxo-1,6-dihydropyridazine-3-carbonitrile

Temperature

0 °C

6-Oxo-1,6-dihydropyridazine-3-carboxamide (J. Chem. Soc. 1948, 2195) (1.1 g, 8.0 mmol) was suspended in dichloromethane (20 mL), cooled to 0° C. then pyridine (1.3 mL, 16 mmol) and trifluoroacetic anhydride (1.2 mL, 8.4 mmol) were added and the reaction was stirred at room temperature for 1 hour. A further 5 mL of pyridine was added to aid solubility and then the reaction was warmed to room temperature and stirred overnight. The mixture was diluted with water (100 mL) and then extracted with dichloromethane (3×100 mL). The combined organic extracts were dried (Na2SO4), the solvent was removed in vacuo, with residual pyridine removed by azeotroping with toluene. The residue was purified by flash chromatography on silica gel (dichloromethane/methanol 95:5 as eluant) to give the title compound as an off-white solid (0.8 g).

1. temperaturethe reaction was warmed to room temperature
2. stirringstirred overnight
3. extractionextracted with dichloromethane (3×100 mL)
4. dry with materialThe combined organic extracts were dried (Na2SO4)
5. customthe solvent was removed in vacuo, with residual pyridine
6. customremoved
7. customby azeotroping with toluene
8. customThe residue was purified by flash chromatography on silica gel (dichloromethane/methanol 95:5 as eluant)

ORD record

ord-ae3fa22e8cb04ebdab4bdce2b40d195a

Source dataset

uspto-grants-2004_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06821972B2