Definition: Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).
olprinone [ E 1020,loprinone hydrochloride,1,2-dihydro-6-methyl-2-oxo-5-(imidazo(1,2-a)pyridin-6-yl)-3-pyridinecarbonitrile,E-1020 ] RN refers to HCl; structure given in first source