反応 #710491

反応方程式

water

sodium borohydride

ethyl (3,5-dichloropyridin-2-yl)(difluoro)acetate

HCl

→

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

溶媒

ethanol

反応条件

後処理

1. 1
   抽出The aequeous phase was extracted three times by 300 mL of ethyl acetate
2. 2
   洗浄the organic phase was successively washed with brine, water
3. 3
   乾燥dried over magnesium sulfate
4. 4
   その他After evaporation of the solvent under vacuum 8.5 g of yellow oil
5. 5
   その他were obtained
6. 6
   ろ過After trituration in diisopropyl ether and filtration 6.8 g (80%) of 2-(3,5-dichloropyridin-2-yl)-2,2-difluoroethanol (Int-9)
7. 7
   その他were obtained as a white solid
8. 8
   その他Mp (melting point)=56° C. (M+1)=228

実験手順

To a solution of 10 g (37 mmol) of ethyl (3,5-dichloropyridin-2-yl)(difluoro)acetate (Int-7) in 60 mL of ethanol, were added portionwise at 0° C., 1.05 g (27.7 mmol) of sodium borohydride. The reaction mixture was stirred below 10° C. for 2 hours. 30 mL of 1 N HCl were then slowly added followed by 500 mL of water. The aequeous phase was extracted three times by 300 mL of ethyl acetate and the organic phase was successively washed with brine, water and dried over magnesium sulfate. After evaporation of the solvent under vacuum 8.5 g of yellow oil were obtained. After trituration in diisopropyl ether and filtration 6.8 g (80%) of 2-(3,5-dichloropyridin-2-yl)-2,2-difluoroethanol (Int-9) were obtained as a white solid. Mp (melting point)=56° C. (M+1)=228. 19F-NMR (235 MHz, CDCl3) δ (ppm): −105.85 (CF2).

出典