反应详情

To a solution of 8.50 g of cyanoacetic acid and 10.1 g of chloroacetamidoxime was added 20.6 g of N,N'-dicyclohexylcarbodiimide with ice-cooling. After stirring for 1 hour at room temperature, the reaction mixture was filtered and the filtrate was concentrated in vacuo. The residue was triturated with 20 ml of ethyl acetate and the insoluble material was filtered off and washed with ethyl acetate. The filtrate was then concentrated in vacuo and the residue was dissolved in 50 ml of toluene. The resultant solution was heated under reflux for 20 minutes with a water separator. After cooling and adding 50 ml of ethyl acetate, the solution was decanted and evaporated in vacuo. The residue was chromatographed on silica gel using chloroform-methanol (50:1) as eluent to give 8.18 g of 3-chloromethyl-5-cyanomethyl-1,2,4-oxadiazole as an oil.

1. temperaturecooling
2. filtrationthe reaction mixture was filtered
3. concentrationthe filtrate was concentrated in vacuo
4. customThe residue was triturated with 20 ml of ethyl acetate
5. filtrationthe insoluble material was filtered off
6. washwashed with ethyl acetate
7. concentrationThe filtrate was then concentrated in vacuo
8. dissolutionthe residue was dissolved in 50 ml of toluene
9. temperatureThe resultant solution was heated
10. temperatureunder reflux for 20 minutes with a water separator
11. temperatureAfter cooling
12. additionadding 50 ml of ethyl acetate
13. customthe solution was decanted
14. customevaporated in vacuo
15. customThe residue was chromatographed on silica gel