4-Aminophenol

4-Aminophenol
IUPAC name 4-Aminophenol
Identifiers
CAS number	123-30-8 Y
PubChem	403
ChemSpider	392 Y
UNII	R7P8FRP05V Y
KEGG	C02372 Y
MeSH	Aminophenols
ChEBI	CHEBI:17602 Y
ChEMBL	CHEMBL1142 Y
Jmol-3D images	Image 1 Image 2
SMILES Oc1ccc(N)cc1 c1cc(ccc1N)O
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
Properties
Molecular formula	C6H7NO
Molar mass	109.13 g/mol
Density	1.13 g/cm3
Melting point	188–190 °C
Boiling point	284 °C
Solubility in water	1.5 g/100 ml (25 °C)
Hazards
EU Index	616-003-00-0
EU classification	Carc. Cat. 2 Muta. Cat. 2 Repr. Cat. 3 Toxic (T)
R-phrases	R20/21, R22, R40 R52, R54, R68
S-phrases	S28, S36, S37 S60, S61
NFPA 704	1 2 0
Flash point	195 °C
Related compounds
Related aminophenols	2-Aminophenol 3-Aminophenol
Related compounds	Aniline Phenol
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

4-Aminophenol is the organic compound with the formula H₂NC₆H₄OH. Typically available as a white powder,^[1] it is commonly used as a developer in black-and-white film, marketed under the name Rodinal.

Reflecting its slight hydrophilic character, the white powder is moderately soluble in alcohols and can be recrystallised from hot water. In the presence of base, it oxidizes readily. The N-methyl and N,N-dimethyl derivatives are of commercial value.

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

Preparation

It is produced from phenol by nitration followed by reduction with iron. Alternatively, the partial hydrogenation of nitrobenzene affords phenylhydroxylamine, which rearranges primarily to 4-aminophenol:^[2]

C₆H₅NO₂ + 2 H₂ → C₆H₅NHOH + H₂O

C₆H₅NHOH → HOC₆H₄NH₂

Uses

p-Aminophenol is a building block compound. Prominently, it is the final intermediate in the industrial synthesis of paracetamol. Treating p-aminophenol with acetic anhydride gives paracetamol:^[3][4][5]

References

1. ^ CRC Handbook of Chemistry and Physics 65th Ed.
2. ^ Mitchell, S.C. & Waring, R.H. “Aminophenols.” In Ullmann’s Encyclopedia of Industrial Chemistry; 2002 Wiley-VCH, doi:10.1002/14356007.a02_099
3. ^ Ellis, Frank (2002). Paracetamol: a curriculum resource. Cambridge: Royal Society of Chemistry. ISBN 0-85404-375-6. 
4. ^ Anthony S. Travis (2007). "Manufacture and uses of the anilines: A vast array of processes and products". In Zvi Rappoport. The chemistry of Anilines Part 1. Wiley. p. 764. ISBN 978-0-470-87171-3. 
5. ^ Elmar Friderichs, Thomas Christoph, Helmut Buschmann (2005), "Analgesics and Antipyretics", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a02_269.pub2