反应详情

A stirred solution of diethyl 2-aminononanedioate (10 g) in ethanol (77 ml) was cooled in ice-water and treated with 2N hydrochloric acid (38.6 ml) followed by a solution of potassium cyanate (6.255 g) in water (20 ml). The cooling bath was removed and the suspension was stirred for 7 hours at room temperature then set aside overnight. The ethanol was evaporated in vacuo and the residue was shaken with water and chloroform; the chloroform phase was separated, washed with water and dried (MgSO4), and the chloroform was evaporated to give an oil which was heated on the steam bath for 6 hours. The resulting oil crystallised on standing at room temperature. The crystals were stirred with ether and collected, affording pure diethyl 2-ureidononanedioate, m.p. 79°-80° C.

1. customThe cooling bath was removed
2. waitthen set aside overnight
3. customThe ethanol was evaporated in vacuo
4. stirringthe residue was shaken with water and chloroform
5. customthe chloroform phase was separated
6. washwashed with water
7. dry with materialdried (MgSO4)
8. customthe chloroform was evaporated
9. customto give an oil which
10. temperaturewas heated on the steam bath for 6 hours
11. customThe resulting oil crystallised
12. customon standing at room temperature
13. stirringThe crystals were stirred with ether
14. customcollected