N-Chloro-N-alkoxyureas: Synthesis, structure and properties

Abstract

The XRD studies of N-chloro-N-alkoxyureas 1, 2 have revealed the high pyramidality of the amide nitrogen in the O-N-Cl group caused by n O-σN-Cl* anomeric effect, the other sequence of this effect is anionic lability of the chlorine atom; nucleophilic substitution at the nitrogen depends on the N′-substitutent nature: chlorine atoms in ureas 1 and 5 are replaced by outer nucleophile whereas, under the same conditions, ureas 2-4 undergo cyclization into 1-alkoxybenzimidazolin- 2-ones 10-12.