反应 #710492

反应方程式

ammonia

triflic anhydride

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

pyridine

→

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

溶剂

brine

acetonitrile

反应条件

后处理

1. 1
   温度while maintaining the temperature below 8° C
2. 2
   workup.ADDITIONwere added
3. 3
   萃取the product extracted three times with 25 mL of ethyl acetate
4. 4
   其他The organic phases were collected
5. 5
   洗涤washed three times with 40 mL of brine
6. 6
   干燥dried over magnesium sulfate
7. 7
   其他Afater evaporation of the solvent under vacuum 1.09 g of brown oil
8. 8
   其他were obtained
9. 9
   其他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)
10. 10
    其他were obtained as a yellow oil, (M+1)=227, 19F-NMR (235 MHz, CDCl3) δ (ppm): −104.80 (CF2)

实验过程

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).

来源