Benzoxazole

Benzoxazole is an aromatic organic compound with a molecular formula C₇H₅NO, a benzene-fused oxazole ring structure, and an odor similar to pyridine.^[1][2] Although benzoxazole itself is of little practical value, many derivatives of benzoxazoles are commercially important.

Benzoxazole

Names
Preferred IUPAC name 1,3-Benzoxazole
Other names 1-Oxa-3-aza-1H-indene
Identifiers
CAS Number	273-53-0 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:38814 Y
ChEMBL	ChEMBL451894 Y
ChemSpider	8873 Y
ECHA InfoCard	100.005.445
PubChem CID	9228
UNII	J233Y1I55I Y
CompTox Dashboard (EPA)	DTXSID8059768
InChI InChI=1S/C7H5NO/c1-2-4-7-6(3-1)8-5-9-7/h1-5H Y Key: BCMCBBGGLRIHSE-UHFFFAOYSA-N Y InChI=1/C7H5NO/c1-2-4-7-6(3-1)8-5-9-7/h1-5H Key: BCMCBBGGLRIHSE-UHFFFAOYAP
SMILES n1c2ccccc2oc1
Properties
Chemical formula	C7H5NO
Molar mass	119.123 g·mol−1
Appearance	White to light yellow solid
Melting point	27 to 30 °C (81 to 86 °F; 300 to 303 K)
Boiling point	182 °C (360 °F; 455 K)
Solubility in water	Insoluble
Hazards
Flash point	58 °C (136 °F; 331 K)
Related compounds
Related compounds	oxazole indole benzofuran
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Being a heterocyclic compound, benzoxazole finds use in research as a starting material for the synthesis of larger, usually bioactive structures. Its aromaticity makes it relatively stable, although as a heterocycle, it has reactive sites which allow for functionalization.

Occurrence and applications

It is found within the chemical structures of pharmaceutical drugs such as flunoxaprofen and tafamidis. Benzoxazole derivatives are also of interest for optical brighteners in laundry detergents.^[3] Benzoxazoles belong to the group of well-known antifungal agents with antioxidant, antiallergic, antitumoral and antiparasitic activity.^[4]

• 
  4,4'-(E)-bis(benzoxazolyl)stilbene is intensely fluorescent and its derivatives are used as optical brighteners
• 
  2,5-bis(benzoxazol-2-yl)thiophene is also intensely fluorescent and its derivatives are used as optical brighteners, e.g. in laundry detergents^[5]

See also

Structural isomers

• Anthranil, an analog with the oxygen atom in position 2
• Benzisoxazole, an analog with the nitrogen atom in position 2

Analogs

• Benzimidazole, an analog with the oxygen replaced by a nitrogen
• Benzothiazole, an analog with the oxygen replaced by a sulfur
• Benzopyrrole or indole, an analog without the oxygen atom
• Benzofuran, an analog without the nitrogen atom