反应 #51799

反应方程式

ammonium acetate

1-(4-fluorophenyl)-2-(2-fluoropyridin-4-yl)ethane-1,2-dione 2-oxime

trimethylacetaldehyde

→

4-[2-tert-butyl-4-(4-fluorophenyl)-1-hydroxy-1H-imidazol-5-yl]pyridin-2(1H)-one

溶剂

acetic acid

反应条件

后处理

1. 1
   温度it was heated
2. 2
   温度to reflux for three hours
3. 3
   其他The acetic acid was removed under reduced pressure
4. 4
   workup.ADDITIONThe pH of the solution was adjusted to 8-10 by addition of solid ammonium hydroxide
5. 5
   萃取was extracted with EtOAc
6. 6
   其他The solvent was removed under reduced pressure
7. 7
   workup.DISSOLUTIONthe crude product was dissolved in methanol with sufficient ethanol
8. 8
   workup.ADDITIONadded to effect dissolution
9. 9
   其他The solvent was removed under reduced pressure
10. 10
    workup.DISSOLUTIONthe product was twice dissolved in ethanol
11. 11
    浓缩concentrated to a small volume under reduced pressure to azeotropically remove water
12. 12
    其他The title compound was recrystallized from ethanol and hexane (28.8 g)

实验过程

To a solution of 1-(4-fluorophenyl)-2-(2-fluoropyridin-4-yl)ethane-1,2-dione 2-oxime (47.3 g, 0.18 mol) in acetic acid (1 L) under nitrogen was added trimethylacetaldehyde (21.6 mL, 0.19 mol) followed by ammonium acetate (277.5 g, 3.6 mol) and then it was heated to reflux for three hours. The acetic acid was removed under reduced pressure and the remaining material was taken up in water. The pH of the solution was adjusted to 8-10 by addition of solid ammonium hydroxide and was extracted with EtOAc. The solvent was removed under reduced pressure and the crude product was dissolved in methanol with sufficient ethanol added to effect dissolution. The solvent was removed under reduced pressure; the product was twice dissolved in ethanol and concentrated to a small volume under reduced pressure to azeotropically remove water. The title compound was recrystallized from ethanol and hexane (28.8 g).

来源