Benzimidazolinone

Benzimidazolinone is an organic compound with the formula C₆H₄(NH)₂CO. Also classified as a heterocyclic compound it is a bicyclic urea. It is a tautomer of 2-hydroxybenzimidazole.

Benzimidazolinone

Names
IUPAC name 2-Benzimidazolinone
Other names 1,3-Dihydro-2H-benzimidazol-2-one 2-Hydroxybenzimidazole N,N′-(1,2-Phenylene)urea
Identifiers
CAS Number	615-16-7 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL2152713
ChemSpider	11490
ECHA InfoCard	100.009.467
EC Number	210-412-4
PubChem CID	11985
UNII	CV8118UZEW
CompTox Dashboard (EPA)	DTXSID0060642
InChI InChI=1S/C7H6N2O/c10-7-8-5-3-1-2-4-6(5)9-7/h1-4H,(H2,8,9,10) Key: SILNNFMWIMZVEQ-UHFFFAOYSA-N
SMILES C1=CC=C2C(=C1)NC(=O)N2
Properties
Chemical formula	C7H6N2O
Molar mass	134.138 g·mol−1
Appearance	white solid
Hazards
GHS labelling:[1]
Pictograms
Signal word	Warning
Hazard statements	H302
Precautionary statements	P264, P270, P301+P317, P330, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis, structure, applications

Pigment Orange 36

The parent compound is prepared by the carbonylation of 1,2-diaminobenzene. The carbonylation can be effected with carbonyldiimidazole.^[2] Like other ureas, it engages in hydrogen bonding, yielding supramolecular structures. Otherwise, the compound is of little interest.

Substituted 2-benzimidazolinones are commercial dyes and pigments. For example 4-amino-2-benzimidazolinone condenses with diketene to give the acetoacetanilide, 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.^[3]

The drug domperidone is a derivative of benzimidazolinone.