Stable activated novel carbamic acid derivatives, preparation method and use forpreparing urea

摘要

Process for the preparation of stable activated derivatives of carbamic acid, comprising at least one protected amino group and an activated carbamic acid function, from an amino acid derivative in which the amino group is protected. The process includes: a) a step of transformation of the -COOH group of the amino acid derivative into a -CON₃ group to obtain an acyl azide; b) a step of transformation of the -CON₃ group of the acyl azide into a -NCO group to obtain an isocyanate; c) a step of treating the isocyanate to obtain a stable derivative of carbamic acid.