反应 #50641

反应方程式

(E)-4-chloro-3-trifluoromethylcinnamamide oxime

triethyl orthoformate

→

(E)-3-(4-chloro-3-trifluoromethyl-styryl)-1,2,4-oxadiazole

收率 71.0%

反应条件

后处理

1. 1
   workup.ADDITIONare added at room temperature
2. 2
   温度at reflux temperature for 2 hours
3. 3
   浓缩the whole batch is then concentrated in vacuo
4. 4
   洗涤washed consecutively with 100 ml of 2N hydrochloric acid, saturated sodium carbonate solution and water
5. 5
   干燥The organic phase is dried over sodium sulphate
6. 6
   workup.DISTILLATIONthe solvent is subsequently distilled off

实验过程

5.2 g (0.02 mol) of (E)-4-chloro-3-trifluoromethylcinnamamide oxime are initially introduced into 50 ml of triethyl orthoformate and 2 drops of boron trifluoride etherate are added at room temperature. The mixture is then stirred at reflux temperature for 2 hours and the whole batch is then concentrated in vacuo. The residue is then taken up in 100 ml of methylene chloride and washed consecutively with 100 ml of 2N hydrochloric acid, saturated sodium carbonate solution and water. The organic phase is dried over sodium sulphate and the solvent is subsequently distilled off. 3.9 g (71.0% of theory) of (E)-3-(4-chloro-3-trifluoromethyl-styryl)-1,2,4-oxadiazole are obtained.

来源