2-Phenylphenol

2-Phenylphenol, or o-phenylphenol, is an organic compound with the formula C₆H₅−C₆H₄OH. It is one of three isomers of monohydroxylated biphenyl.^[2] It is a white solid. It is a biocide used as a preservative^[3] with E number E231 and under the trade names Dowicide, Torsite, Fungal, Preventol, Nipacide and many others.

2-Phenylphenol

Ball-and-stick model of 2-Phenylphenol
Names
Preferred IUPAC name [1,1′-Biphenyl]-2-ol
Other names 2-Phenylphenol 2-Biphenylol o-Phenylphenol Biphenylol 2-Hydroxybiphenyl Orthophenyl phenol o-Xenol Orthoxenol
Identifiers
CAS Number	90-43-7 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:17043
ChEMBL	ChEMBL108829 Y
ChemSpider	13839012 Y
ECHA InfoCard	100.001.812
EC Number	201-993-5
E number	E231 (preservatives)
KEGG	D08367 Y
PubChem CID	7017
RTECS number	DV5775000
UNII	D343Z75HT8 Y
UN number	3077
CompTox Dashboard (EPA)	DTXSID2021151
InChI InChI=1S/C12H10O/c13-12-9-5-4-8-11(12)10-6-2-1-3-7-10/h1-9,13H Y Key: LLEMOWNGBBNAJR-UHFFFAOYSA-N Y InChI=1/C12H10O/c13-12-9-5-4-8-11(12)10-6-2-1-3-7-10/h1-9,13H Key: LLEMOWNGBBNAJR-UHFFFAOYAF
SMILES Oc2ccccc2c1ccccc1
Properties
Chemical formula	C12H10O
Molar mass	170.211 g·mol−1
Density	1.293 g/cm3
Melting point	55.5 to 57.5 °C (131.9 to 135.5 °F; 328.6 to 330.6 K)
Boiling point	280 to 284 °C (536 to 543 °F; 553 to 557 K)
Pharmacology
ATC code	D08AE06 (WHO)
Hazards
GHS labelling:[1]
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335, H400
Precautionary statements	P261, P264, P264+P265, P271, P273, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P391, P403+P233, P405, P501
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

Uses

The primary use of 2-phenylphenol is as an agricultural fungicide. It is generally applied post-harvest as a fungicide used for waxing citrus fruits.^[3]

It is also used for disinfection of seed boxes. It is a general surface disinfectant, used in households, hospitals, nursing homes, farms, laundries, barber shops, and food processing plants. It can be used on fibers and other materials. It is used to disinfect hospital and veterinary equipment. Other uses are in rubber industry and as a laboratory reagent. It is also used in the manufacture of other fungicides, dye stuffs, resins and rubber chemicals. The sodium salt of orthophenyl phenol, sodium orthophenyl phenol, is a preservative, used to treat the surface of citrus fruits.^[4]

2-Phenylphenol is a precursor to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, a commercial fire retardant.

Preparation

It can be prepared by condensation of cyclohexanone to give cyclohexenylcyclohexanone. The latter undergoes dehydrogenation to give 2-phenylphenol. Another route, it is a significant and recovered by product of the reaction of chlorobenzene with alkali which primarily gives phenol.^[3]

Safety

LD50 (rats) is 2700 to 3000 mg/kg. 2-Phenylphenol is no longer a permitted food additive in the European Union but is still allowed as a post-harvest treatment in 4 EU countries.^[3] As a fungicide in food packaging orthophenyl phenol may migrate into the contents.^[5]