Imidazoline is a nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

-containing heterocycle

Heterocyclic compound

A heterocyclic compound is a cyclic compound which has atoms of at least two different elements as members of its ring. The counterparts of heterocyclic compounds are homocyclic compounds, the rings of which are made of a single element....

 with formula C₃H₆N₂, derived from imidazole

Imidazole

Imidazole is an organic compound with the formula C3H4N2. This aromatic heterocyclic is a diazole and is classified as an alkaloid. Imidazole refers to the parent compound, whereas imidazoles are a class of heterocycles with similar ring structure, but varying substituents...

. The ring contains an imine

Imine

An imine is a functional group or chemical compound containing a carbon–nitrogen double bond, with the nitrogen attached to a hydrogen atom or an organic group. If this group is not a hydrogen atom, then the compound is known as a Schiff base...

 bond, and the carbons at the 4 and 5 positions are singly bonded, rather than doubly bonded for the case of imidazole. Imidazolines are structurally related to guanidine

Guanidine

Guanidine is a crystalline compound of strong alkalinity formed by the oxidation of guanine. It is used in the manufacture of plastics and explosives. It is found in urine as a normal product of protein metabolism. The molecule was first synthesized in 1861 by the oxidative degradation of an...

s and amidine

Amidine

Amidines are a class of oxoacid derivatives.The oxoacid from which an amidine is derived must be of the form RnEOH, where R is a substituent...

s.




Like imidazole, imidazoline-based compounds have been used as N-heterocyclic carbene ligands on various transition metals. It is found in the commercially available second generation Grubbs' catalyst

Grubbs' catalyst

Grubbs' Catalyst is a transition metal carbene complex named after Robert H. Grubbs, the chemist who first synthesized it. There are two generations of the catalyst, as shown on the right. In contrast to other olefin metathesis catalysts, Grubbs' Catalysts tolerate other functional groups in the...

.

Biological role

Many imidazolines are biologically active. Most bio-active derivatives bear a substituent (aryl

Aryl

In the context of organic molecules, aryl refers to any functional group or substituent derived from an aromatic ring, be it phenyl, naphthyl, thienyl, indolyl, etc....

 or alkyl group) on the carbon between the nitrogen centers. Some generic names include oxymetazoline

Oxymetazoline

Oxymetazoline is a selective alpha-1 agonist and partial alpha-2 agonist topical decongestant, used in the form of Oxymetazoline hydrochloride, in products such as Afrin, Dristan, Nasivin, Logicin, Vicks Sinex, Visine L.R., Sudafed OM, and Zicam. It was developed from Xylometazoline at E.Merck...

, xylometazoline

Xylometazoline

Xylometazoline is a drug which is used as a topical nasal decongestant. It is applied directly into the nose, either as a spray or as drops....

, tetrahydrozoline

Tetrahydrozoline

Tetrahydrozoline, a derivative of imidazoline, is found in over-the-counter eye drops and nasal sprays. Other derivatives include naphazoline, oxymetazoline, and xylometazoline. Poisoning can result from an overdose....

, and naphazoline

Naphazoline

Naphazoline is the common name for 2--2-imidazoline hydrochloride. It is a sympathomimetic agent with marked alpha adrenergic activity. It is a vasoconstrictor with a rapid action in reducing swelling when applied to mucous membrane...

.