A Simple One-Pot Preparation of N,N′-Unsymmetrical Ureas from N-Boc Protected Primary Anilines and Amines

Synlett

Volumn 1996, Issue 6, 1996, Pages 507-508

  Lamothe, Marie ^a   Perez, Michel ^a   Colovray Gotteland, Véronique ^a   Halazy, Serge ^a  

^a INSTITUT DE RECHERCHE PIERRE FABRE   (France)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000095112     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-1996-5476     Document Type: Article

References (17)

1. Greene, T. W.; Wuts, P. G. M. Protective Groups in Organic Synthesis, 2nd ed.; Wiley: New York, 1991, p327; Kocienski, P. J. Protecting Groups; Thieme, Stuttgart, 1994, p192.
2. Greene, T. W.; Wuts, P. G. M. Protective Groups in Organic Synthesis, 2nd ed.; Wiley: New York, 1991, p327; Kocienski, P. J. Protecting Groups; Thieme, Stuttgart, 1994, p192.
3. Myers, A. G.; Yoon, T. Tetrahedron Lett. 1995, 36, 9429.
4. Vishnyakova, T. P.; Golubeva, I. A.; Glebova, E. V. Russ. Chem. Rev. 1985, 54, 249.
5. Majer, P.; Randad, R. S. J. Org. Chem. 1994, 59, 1937.
6. a) Izdebski, J.; Pawlak, D. Synthesis 1989, 423.
7. b) Freer, R.; McKillop, A. Synth. Commun. 1996, 26, 331.
8. Overman, L. E.; Taylor, G. F.; Petty, C. B.; Jessup, P. J. J. Org. Chem. 1978, 43, 2164.
9. Madelmont, J. C.; Godeneche, D.; Parry, D.; Duprat, J.; Chabard, J. L.; Plagne, R.; Mathe, G.; Meyniel, G. J. Med Chem. 1985, 28, 1346.
10. Knölker, H.-J.; Braxmeier, T.; Schlechtingen, G. Angew. Chem. Int. Ed. Engl. 1995, 34, 2497.
11. Hoeve, W.; Kruse, C. G.; Luteyn, J. M.; Thiecke, J. R. G.; Wynberg, H. J. Org. Chem. 1993, 58, 5101.
12. The enantiomeric excess of both starting carbamates were evaluated by chiral HPLC and were found to be 99.6% ee for the (L) isomer and 99% ee for the (D) isomer. Experiments were performed at ambient temperature and with UV detection at 220 nm. A chiralcel OD column (250 x 4.6 mm I.D., Interchim, Montluçon, France) was used with the following mobile phase: n-hexane - 2-propanol 90 - 10; flow rate, 0.5 ml/min.
13. HPLC conditions for the ureas: Chiralcel OD (250 x 4.6 mm I.D.), n-hexane - ethanol 70 - 30 modified with 0.1% diethylamine, 220 nm, 0.5 ml/min.
14. a) Menger, F. M.; Glass, L. E. J. Org. Chem. 1974, 39, 2469.
15. b) Satchell, D. P. N.; Satchell, R. S. Chem. Soc. Rev. 1975, 4, 231.
16. Williams, A.; Douglas, K. T. Chem. Rev. 1975, 75, 627.
17. Method A: A THF solution of the amine anion prepared from amine 2 and n-BuLi is added dropwise at room temperature to a solution of carbamate 1 in THF. The reaction is then heated at reflux for the given time. Method B: The carbamate 1 and the amine 2 are dissolved in the solvent at room temperature prior to the addition of the base. The reaction is then heated at reflux for the given time. Method C: A THF solution of the amine anion prepared from amine 2 and n-BuLi is added dropwise at -78°C to a solution of carbamate 1 in THF. The reaction is then heated at reflux for the given time.