Substituted Ureas and Their Analogues Containing Framework Fragments. III. Features of the Synthesis of Monoimines Based on Camphor and Aliphatic Diamines

The study is aimed at the selective synthesis of monoimines from camphor and aliphatic diamines. Three diamines were selected: 1,2-diaminoethane, 1,3-diaminopropane and 1,6-diaminohexane, the latter providing the highest selectivity (over 90%) at a 5-fold molar excess. Comparative analysis showed that the selectivity for 1,6-diaminohexane and 1,3-diaminopropane remains high, whereas for 1,2-diaminoethane it decreases to 77.4%, which is well explained by the reaction mechanism of the studied catalyzed by zinc carboxylates.