咪唑啉是由两个双键中的一个还原而衍生自咪唑的一类杂环。已知三种异构体，2-咪唑啉，3-咪唑啉和4-咪唑啉。2和3-咪唑啉含有亚胺中心，而4-咪唑啉含有烯烃基团。2-咪唑啉基团在几种药物中均有发生。
2,5-Dioxopyrrolidin-1-yl 6-((4R,5S)-5-methyl-2-oxoimidazolidin-4-yl)hexanoate
2-(4-((2,4-Dioxothiazolidin-5-ylidene)methyl)phenoxy)acetic acid
Methyl (Z)-2-(5-((2,4-dioxothiazolidin-5-ylidene)methyl)furan-2-yl)benzoate
6'-Bromo-8'-methyl-2'H-spiro[cyclohexane-1,3'-imidazo[1,5-a]pyridine]-1',5'-dione
5-((5-(2,3-Dichlorophenyl)furan-2-yl)methylene)thiazolidine-2,4-dione
3-(4-Chlorophenyl)-1,4-diazaspiro[4.5]dec-3-ene-2-thione
1-(4-Chlorophenyl)-1H-imidazole-2(3H)-thione
1-(Furan-2-ylmethyl)-5-phenyl-1H-imidazole-2(3H)-thione
2-Oxoimidazolidine-1-carbonyl chloride
3-(2-Methoxyphenyl)-1,4,7-triazaspiro[4.4]non-3-en-2-one
1-Methyl-3-phenyl-1,4,7-triazaspiro[4.4]non-3-en-2-one
1-Methyl-2-(piperazin-1-yl)-1H-imidazol-5(4H)-one
