تفاعل #82821

معادلة التفاعل

4-nitrobenzamide oxime

ethyl chlorooxoacetate

borontrifluoride

→

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

المذيبات

dioxane

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwas refluxed for 1 hour
2. 2
   درجة الحرارةThe whole mixture was refluxed for 12 hours
3. 3
   أخرىthe solvent was evaporated in vacuo
4. 4
   workup.ADDITIONThe residue was diluted with ethyl acetate (100 ml)
5. 5
   غسيلwashed with a saturated potassium carbonate aqueous solution
6. 6
   تجفيفdried over magnesium sulfate
7. 7
   أخرىevaporated in vacuo
8. 8
   أخرىThe 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
    أخرىwere collected
11. 11
    أخرىevaporated in vacuo

الإجراء التجريبي

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.

المصدر