Benzimidazolinone is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the formula . Also classified as a

heterocyclic compound A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic organic chemistry is the branch of organic chemistry dealing with the synthesis, proper ...

it is a bicyclic

urea Urea, also called carbamide (because it is a diamide of carbonic acid), is an organic compound with chemical formula . This amide has two Amine, amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest am ...

. It is a

tautomer In chemistry, tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the reloca ...

of 2-hydroxybenzimidazole.

Synthesis, structure, applications

The parent compound is prepared by the carbonylation of

1,2-diaminobenzene ''o''-Phenylenediamine (OPD) is an organic compound with the formula C6H4(NH2)2. This aromatic diamine is an important precursor to many heterocyclic compounds. OPD is a white compound although samples appear darker owing to oxidation by air. I ...

. The carbonylation can be effected with

carbonyldiimidazole 1,1'-Carbonyldiimidazole (CDI) is an organic compound with the molecular formula . It is a white crystalline solid. It is often used for the coupling of amino acids for peptide synthesis and as a reagent in organic synthesis. Preparation CDI ca ...

. Like other

s, it engages in

hydrogen bonding In chemistry, a hydrogen bond (H-bond) is a specific type of molecular interaction that exhibits partial covalent character and cannot be described as a purely electrostatic force. It occurs when a hydrogen (H) atom, Covalent bond, covalently b ...

, yielding

supramolecular Supramolecular chemistry refers to the branch of chemistry concerning chemical systems composed of a discrete number of molecules. The strength of the forces responsible for spatial organization of the system range from weak intermolecular forces, ...

structures. Otherwise, the compound is of little interest. Substituted 2-benzimidazolinones are commercial dyes and

pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...

s. For example 4-amino-2-benzimidazolinone condenses with

diketene Diketene is an organic compound with the molecular formula , and which is sometimes written as . It is formed by dimerization of ketene, . Diketene is a member of the oxetane family. It is used as a reagent in organic chemistry. It is a colorle ...

to give the

acetoacetanilide Acetoacetanilide is an organic compound with the formula CH3C(O)CH2C(O)NHC6H5. It is the acetoacetamide derivative of aniline. It is a white solid that is poorly soluble in water. This chemical and many related compounds (prepared from various ...

, which undergoes diazo coupling with various aryldiazonium salts. In this way pigment orange 36 and pigment yellow 154 are produced. These pigments are used in paints and plastics.{{cite book , doi=10.1002/0471238961.151807011001060605.a01.pub2 , chapter=Pigments, Organic , title=Kirk-Othmer Encyclopedia of Chemical Technology , date=2004 , last1=Jaffe , first1=Edward E. , isbn=978-0-471-48494-3 The drug

domperidone Domperidone, sold under the brand name Motilium among others, is a dopamine antagonist medication which is used to treat nausea and vomiting and certain gastrointestinal problems like gastroparesis (delayed gastric emptying). It raises the ...

is a derivative of benzimidazolinone.

References

Ureas Organic pigments Shades of orange Benzimidazolines