N,N′-Di­benzyl­ethyl­enedi­ammonium dichloride

Abstract

Modulation of the phenyl groups in N,N′-di­benzyl­ethyl­enedi­ammonium dichloride in P2₁/n allows for the formation of a network of strong N—H⋯Cl hydrogen bonds and C—H⋯Cl inter­actions and breaks C2/c symmetry.

The isolation and crystalline structure of N,N′-di­benzyl­ethyl­enedi­ammonium dichloride, C₁₆H₂₂N₂²⁺·2Cl⁻, is reported. This was obtained as an unintended product of an attempted Curtius rearrangement that involved benzyl­amine as one of the reagents and 1,2-di­chloro­ethane as the solvent. Part of a series of reactions of a course-based undergraduate research experience (CURE), this was not the intended reaction outcome. The goal of the course was to engage students as active participants in a laboratory experience which applies the foundational techniques of a synthetic organic laboratory, using the Curtius rearrangement as a tool for the assembly of medicinally significant scaffolds. The isolation of the title compound, N,N′-di­benzyl­ethyl­enedi­ammonium dichloride, the result of the 1,2-di­chloro­ethane solvent outcompeting the Curtius iso­cyanate inter­mediate in the reaction with the nucleophilic amine, confirms the importance of conducting research at the undergraduate level where the outcome is not predetermined. The solid-state structure of N,N′-di­benzyl­ethyl­enedi­ammonium dichloride was found to feature an all-trans methyl­ene-ammonium backbone. Strong N—H⋯Cl hydrogen bonds and C—H⋯Cl inter­actions lead to a layered structure with pseudo-translational symmetry emulating a C-centered setting. Different phenyl torsion angles at each end of the mol­ecule enable a more stable packing by allowing stronger hydrogen-bonding inter­actions, leading to a more ordered but lower symmetry and modulated structure in P2₁/n.