反应详情

To a stirring solution of 23.5 g (0.2 mole) 2,2-dimethylbutanoic acid in 150 ml. acetone, there is added 30 ml. triethylamine. The temperature is lowered to 0°, and 21.1 ml. (0.22 mol) ethyl chloroformate are added over one-half hour, keeping the temperature at 0°. At the end of the addition, the mixture is stirred for 15 minutes, keeping the temperature at 0°. At the end of this period, a solution of 26.0 g. (0.4 mole) sodium azide in 75 ml. of water is added over one-half hour, keeping the temperature at 0°. The resulting mixture is stirred one hour at 0°. At the end of this period, the mixture is poured into 750 ml. of ice water. This mixture is extracted 4 times with 200 ml. toluene. The toluene portions are combined and dried. The toluene solution is added dropwise to 150 ml. of toluene refluxing in a nitrogen atmosphere. After the addition is complete, the solution is heated to reflux until the IR shows the disappearance of the azide peak (about two and one-half hours). The solution is then cooled and 14.0 g. (0.2 mole) 2-aminopropionitrile are added. The resulting mixture is refluxed for 5 hours. At the end of this period, the toluene is removed at reduced pressure. The residue is put through a column of Silica AR CC7 using toluene:ethyl acetate, 80:20 as the liquid phase. The desired portions are combined and the toluene and ethyl acetate are removed under reduced pressure. The residue is recrystallized from ethyl acetate/cyclohexane to give the product, N-(1-cyanoethyl)-N'-(1,1-dimethylpropyl)urea, m.p. 129°-30°. Anal. Calcd. for C8H17N3O: C: 58.99, H: 9.35, N: 22.93; Found: C: 58.82, H: 9.13, N: 22.92.

1. customis lowered to 0°
2. customat 0°
3. additionAt the end of the addition
4. customat 0°
5. customat 0°
6. stirringThe resulting mixture is stirred one hour at 0°
7. additionAt the end of this period, the mixture is poured into 750 ml
8. extractionThis mixture is extracted 4 times with 200 ml
9. customdried
10. additionThe toluene solution is added dropwise to 150 ml
11. additionAfter the addition
12. temperaturethe solution is heated
13. temperatureto reflux until the IR
14. temperatureThe solution is then cooled
15. temperatureThe resulting mixture is refluxed for 5 hours
16. customAt the end of this period, the toluene is removed at reduced pressure
17. customthe toluene and ethyl acetate are removed under reduced pressure
18. customThe residue is recrystallized from ethyl acetate/cyclohexane