Imidazolidinone

Imidazolidinones feature a saturated C3N2 nucleus, except for the presence of a urea or amide functional group in the 2 or 4 positions.

Drugs featuring this ring system include emicerfont, imidapril, and azlocillin.

4-Imidazolidinones can be prepared from phenylalanine in two chemical steps (amidation with methylamine followed by condensation reaction with acetone): Imidazolidinone catalyst work by forming an iminium ion with carbonyl groups of α,β-unsaturated aldehydes (enals) and enones in a rapid chemical equilibrium.

[2] Drugs featuring the 4-imidazolidinone ring include hetacillin, NNC 63-0532, spiperone, and spiroxatrine.

Examples include imidazol-4-one-5-propionic acid, a product of the catabolism of histidine, and imazaquin, a member of the imidazolinone class of herbicide.