N-Urethane protection of amines and amino acids in an ionic liquid

An efficient, solvent-free protocol for the N-fluorenylmethoxycarbonylation and N-benzyloxycarbonylation ofamines is described. The reaction of aliphatic and aromatic amines with FmocOSu and Cbz-Osu in [Bmim]-[BF4] at room temperature afforded the corresponding N-urethane derivatives in excellent yields and donot require any further purification. The method has been extended to the N-Fmoc and N-Cbz protectionof amino acids. Absence of bases, very short reaction times, high yields, selectivity and ease of productseparation are some advantages of this protocol