2-imidazoline

2-Imidazoline (Preferred IUPAC name: '4,5-dihydro-1H-imidazole') is one of three isomers of the nitrogen-containing heterocycle imidazoline, with the formula C3H6N2. The 2-imidazolines are the most common imidazolines commercially, as the ring exists in some natural products and some pharmaceuticals. They also have been examined in the context of organic synthesis, coordination chemistry, and homogeneous catalysis.

== Synthesis == thumb|left|400px|Synthesis of imidazolines from nitrile and from ester precursors. A variety of routes exist for the synthesis of imidazolines, with the most common methods involving the condensation of 1,2-diamines (e.g. ethylenediamine) with nitriles or esters. The nitrile based route is essentially a cyclic Pinner reaction; it requires high temperatures and acid catalysis and is effective for both alkyl and aryl nitriles.