反应详情

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.

1. additionare added at room temperature
2. temperatureat reflux temperature for 2 hours
3. concentrationthe whole batch is then concentrated in vacuo
4. washwashed consecutively with 100 ml of 2N hydrochloric acid, saturated sodium carbonate solution and water
5. dry with materialThe organic phase is dried over sodium sulphate
6. distillationthe solvent is subsequently distilled off