Tetrahydrofuran → 2-Cyano-3-fluoropyridine

Temperatur

2.5 °C

30 g of 3-Fluoropyridine-2-carboxamide (C), 120 mL of THF and 768.5 mL of TEA were taken in a reaction flask and cooled to 0-5° C. To this mixture, 72.2 mL of Trifluoroacetic anhydride (in 30 mL of THF) was added dropwise over a period of 30 minutes keeping the reaction temperature below 5° C. (0° C. to 5° C.) and the RM was stirred for 2 hours 30 minutes at a temperature below 10° C. (5° C. to 10° C.). After completion of the reaction, 150 mL of 20% Na2CO3 solution was added dropwise to the RM while maintaining the temperature below 10° C. (5° C. to 5° C.), followed by addition of 360 mL of purified water. The RM was brought to room temperature (RT) and extracted with dichloromethane (MDC) and the organic layer was washed with 300 mL purified water, 150 mL of 2% dil HCl, followed by purified water and brine. The organic layer was dried over Na2SO4 and distilled under vacuum, resulting in the titled compound as a dark brown viscous oily mass. Crude Yield: 22-24 g.

1. customthe reaction temperature below 5° C. (0° C. to 5° C.)
2. additionwas added dropwise to the RM
3. temperaturewhile maintaining the temperature below 10° C. (5° C. to 5° C.)
4. customwas brought to room temperature
5. custom(RT)
6. extractionextracted with dichloromethane (MDC)
7. washthe organic layer was washed with 300 mL
8. custompurified water, 150 mL of 2% dil HCl
9. customby purified water and brine
10. dry with materialThe organic layer was dried over Na2SO4
11. distillationdistilled under vacuum

ORD-Eintrag

ord-6b91dab580374ebf8e71fd1c5aba3336

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08541580B2