反応 #82821

反応方程式

4-nitrobenzamide oxime

ethyl chlorooxoacetate

borontrifluoride

→

5-ethoxycarbonyl-3-(4-nitrophenyl)-1,2,4-oxadiazole

溶媒

dioxane

反応条件

後処理

1. 1
   温度was refluxed for 1 hour
2. 2
   温度The whole mixture was refluxed for 12 hours
3. 3
   その他the solvent was evaporated in vacuo
4. 4
   workup.ADDITIONThe residue was diluted with ethyl acetate (100 ml)
5. 5
   洗浄washed with a saturated potassium carbonate aqueous solution
6. 6
   乾燥dried over magnesium sulfate
7. 7
   その他evaporated in vacuo
8. 8
   その他The residue was purified by column chromatography on silica gel with a mixture of dichloromethane and hexane (1:1) as eluent
9. 9
   workup.ADDITIONThe fractions containing the object product
10. 10
    その他were collected
11. 11
    その他evaporated in vacuo

実験手順

A mixture of 4-nitrobenzamide oxime (4 g) and ethyl chlorooxoacetate (3.01 g) in dioxane (200 ml) was refluxed for 1 hour, and then borontrifluoride (1 ml) was added thereto. The whole mixture was refluxed for 12 hours. After being cooled to room temperature, the solvent was evaporated in vacuo. The residue was diluted with ethyl acetate (100 ml), washed with a saturated potassium carbonate aqueous solution, dried over magnesium sulfate and evaporated in vacuo. The residue was purified by column chromatography on silica gel with a mixture of dichloromethane and hexane (1:1) as eluent. The fractions containing the object product were collected and evaporated in vacuo to afford 5-ethoxycarbonyl-3-(4-nitrophenyl)-1,2,4-oxadiazole.

出典