Imidazoline scaffold in medicinal chemistry: a patent review (2012-2015).
Until very recently, the 'imidazoline drugs' were perceived as a class of central and/or peripheral sympatholytics and vasodilators acting at either the imidazoline binding sites and/or α-adrenergic receptors. However, in recent years it has become evident that the imidazoline scaffold is also contained in synthetic agents that exhibit a broad spectrum of biological activities. This review provides an insight into the patents filed in the years 2012-2015, and considers 2-imidazoline-containing compounds with proven biological properties. Special attention is paid to agents for which practical applications as active ingredients of pharmaceutical compositions, diagnostic imaging agents, insecticides and herbicides, may be found. 2-Substituted imidazolines can exist in multiple tautomeric forms. The implication is that imidazolines and their imidazolidine tautomers cannot be regarded as isofunctional structures and the term 'imidazoline scaffold' should be treated with caution. Nevertheless, for medicinal chemists the progress made in development of both the imidazoline- and imidazolidine-containing agents useful for the treatment of neurodegenerative, inflammatory, autoimmune, cancer, and infectious diseases is of the utmost importance.