Reacción #710492

Ecuación de reacción

ammonia

triflic anhydride

2-(3,5-dichloropyridin-2-yl)-2,2-difluoroethanol

pyridine

→

2-(3,5-dichloropyridin-2-yl)-2,2-difluoroethanamine

Disolventes

brine

acetonitrile

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawhile maintaining the temperature below 8° C
2. 2
   workup.ADDITIONwere added
3. 3
   Extracciónthe product extracted three times with 25 mL of ethyl acetate
4. 4
   OtroThe organic phases were collected
5. 5
   Lavadowashed three times with 40 mL of brine
6. 6
   Secadodried over magnesium sulfate
7. 7
   OtroAfater evaporation of the solvent under vacuum 1.09 g of brown oil
8. 8
   Otrowere obtained
9. 9
   OtroAfter purification by column chromatography on silica gel (heptane/ethyl acetate gradient) 0.65 g (50%) of 2-(3,5-dichloropyridin-2-yl)-2,2-difluoroethanamine (IIa-15)
10. 10
    Otrowere obtained as a yellow oil, (M+1)=227, 19F-NMR (235 MHz, CDCl3) δ (ppm): −104.80 (CF2)

Procedimiento

To a solution of 1.3 g (5.7 mmol) of 2-(3,5-dichloropyridin-2-yl)-2,2-difluoroethanol (Int-9) in dry acetonitrile under argon, were added 0.744 mL (9.12 mmol) of dry pyridine. The reaction mixture was cooled to 0° C. and 1.06 mL (6.27 mmol) of triflic anhydride were added dropwise in 15 min while maintaining the temperature below 8° C. The reaction mixture was stirred at 0° C. for additional 30 min 9.9 mL of a 28% w/w aqueous solution of ammonia (144 mmol) were added and the reaction mixture was stirred at room temperature for 2 days. The reaction mixture was diluted with 50 mL of brine and the product extracted three times with 25 mL of ethyl acetate. The organic phases were collected, washed three times with 40 mL of brine and dried over magnesium sulfate. Afater evaporation of the solvent under vacuum 1.09 g of brown oil were obtained. After purification by column chromatography on silica gel (heptane/ethyl acetate gradient) 0.65 g (50%) of 2-(3,5-dichloropyridin-2-yl)-2,2-difluoroethanamine (IIa-15) were obtained as a yellow oil, (M+1)=227, 19F-NMR (235 MHz, CDCl3) δ (ppm): −104.80 (CF2).

Fuente