Contents

4-Aminophenol

4-Aminophenol

Names
Preferred IUPAC name 4-Aminophenol[1]
Other names p-Aminophenol para-Aminophenol
Identifiers
CAS Number	123-30-8 Y
3D model (JSmol)	Interactive image Interactive image
ChEBI	CHEBI:17602 Y
ChEMBL	ChEMBL1142 Y
ChemSpider	392 Y
ECHA InfoCard	100.004.198
KEGG	C02372 Y
MeSH	Aminophenols
PubChem CID	403
UNII	R7P8FRP05V Y
CompTox Dashboard (EPA)	DTXSID3024499
InChI InChI=1S/C6H7NO/c7-5-1-3-6(8)4-2-5/h1-4,8H,7H2 Y Key: PLIKAWJENQZMHA-UHFFFAOYSA-N Y InChI=1/C6H7NO/c7-5-1-3-6(8)4-2-5/h1-4,8H,7H2 Key: PLIKAWJENQZMHA-UHFFFAOYAD
SMILES Oc1ccc(N)cc1 c1cc(ccc1N)O
Properties
Chemical formula	C6H7NO
Molar mass	109.128 g·mol−1
Appearance	Colorless to reddish-yellow crystals
Density	1.13 g/cm3
Melting point	187.5 °C (369.5 °F; 460.6 K)
Boiling point	284 °C (543 °F; 557 K)
Solubility in water	1.5 g/100 mL
Solubility	Very soluble in dimethylsulfoxide Soluble in acetonitrile, ethyl acetate, and acetone Slightly soluble in toluene, diethyl ether, and ethanol Negligible solubility in benzene and chloroform
log P	0.04
Acidity (pKa)	5.48 (amino; H2O) 10.30 (phenol; H2O)[2]
Structure
Crystal structure	orthorhombic
Thermochemistry
Std enthalpy of formation (ΔfH⦵298)	-190.6 kJ/mol
Hazards
NFPA 704 (fire diamond)	2 1 0
Flash point	195 °C (383 °F; 468 K) (cc)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	671 mg/kg
Related compounds
Related aminophenols	2-Aminophenol 3-Aminophenol
Related compounds	Aniline Phenol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Chemical compound

4-Aminophenol (orpara-aminophenolorp-aminophenol) is the organic compound with the formulaH₂NC₆H₄OH. Typically available as a white powder,^[3] it was commonly used as a developer for black-and-white film, marketed under the name Rodinal.

Reflecting its slightly hydrophilic character, the white powder is moderately soluble in alcohols and can be recrystallized from hot water. In the presence of a base, it oxidizes readily. The methylated derivatives N-methylaminophenol and N,N-dimethylaminophenol are of commercial value.

The compound is one of three isomeric aminophenols, the other two being 2-aminophenol and 3-aminophenol.

Preparation

From phenol

It is produced from phenolbynitration followed by reduction with iron. Alternatively, the partial hydrogenationofnitrobenzene affords phenylhydroxylamine, which rearranges primarily to 4-aminophenol:^[4]

C₆H₅NO₂ + 2 H₂ → C₆H₅NHOH + H₂O

C₆H₅NHOH → HOC₆H₄NH₂

From nitrobenzene

It can be produced from nitrobenzene by electrolytic conversion to phenylhydroxylamine, which spontaneously rearranges to 4-aminophenol.^[5]

Uses

4-Aminophenol is a building block used in organic chemistry. Prominently, it is the final intermediate in the industrial synthesis of paracetamol. Treating 4-aminophenol with acetic anhydride gives paracetamol:^[6][7][8]

References