Reaction of Amide and Sodium Azide for the Synthesis of Acyl Azide, Urea, and Iminophosphorane.

Amides reacted with NaN 3 to give the acyl azides in DMF at 25 °C and produce the symmetrical ureas in THF/H 2 O at 80 °C via the sequential reaction of acyl substitution and Curtius rearrangement. All acyl azides were also obtained from the secondary amides via sequential reaction of p -toluenesulfonyl chloride and NaN 3 . In addition, keto-stabilized iminophosphoranes were prepared from a one-pot reaction of amides, NaN 3 , and phosphines.