反応 #710492

反応方程式

ammonia

triflic anhydride

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

pyridine

→

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

溶媒

brine

acetonitrile

反応条件

後処理

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

実験手順

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).

出典