反应详情

温度

50 °C

tert-Butyl 3-oxo-(Z)-2-[(2S,4S)-1-(4-nitrobenzyloxycarbonyl)-2-(4-nitrobenzyloxycarbonyl)pyrrolidine-4-yloxyimino]butyrate (2.19 g, 3.56 mmol) in acetic acid (7 ml) was treated with sulphuryl chloride (2.89 ml, 4.81 g, 35.6 mmol) and the mixture was heated at 50° C. for 2.75 h. The mixture was evaporated under reduced pressure, and toluene added to the residue an the solvent evaporated. The was repeated a further three times. The residue was partially dissolved in ethanol (15 ml) and thiourea (271 mg, 3.56 mmol) was added, followed by N,N-dimethylaniline (0.9 ml, 860 mg, 7.1 mmol). Ethanol (15 ml) was added and the mixture was warmed to effect dissolution, the mixture was stirred at room temperture for 1.5 h, then warmed again to dissolve the material, and stirred a further 0.5 h. The ethanol was then removed by evaporation under reduced pressure and a mixture of water/ethyl acetate/n-butanol added. The pH was adjusted to 2 and the layers separated. The aqueous layer was again extracted with n-butanol (x2). The butanol extracts were combined and evaporated under reduced pressure. Ethanol was added to the residue and removed under reduced pressure, followed by toluene (x3) to leave a solid which was dried over P2O5 in vacuo to give the crude title compound (2.03 g); νmax (KBr) 3383, 1745, 1710, 1630, 1607, 1521, 1432, 1404 and 1347 cm-1.

1. customThe mixture was evaporated under reduced pressure, and toluene
2. additionadded to the residue an the solvent
3. customevaporated
4. dissolutionThe residue was partially dissolved in ethanol (15 ml)
5. temperaturethe mixture was warmed
6. dissolutiondissolution
7. temperaturewarmed again
8. dissolutionto dissolve the material
9. stirringstirred a further 0.5 h
10. customThe ethanol was then removed by evaporation under reduced pressure
11. additiona mixture of water/ethyl acetate/n-butanol
12. additionadded
13. customthe layers separated
14. extractionThe aqueous layer was again extracted with n-butanol (x2)
15. customevaporated under reduced pressure
16. additionEthanol was added to the residue
17. customremoved under reduced pressure
18. customto leave a solid which
19. dry with materialwas dried over P2O5 in vacuo