4-Aminophenol

P-AMINOPHENOL · PARA AMINO PHENOL · aminophenol · p-Aminofenol · AMINOPHENOL-4 · Mesalazine EP IMpurity A · AZOL · CAS:123-30-8

https://huagongshe.com/en/chemical/403

Identifiers & Physical Properties

CAS No.	123-30-8
Molecular formula	C6H7NO
Average molar mass	109.13 g/mol
Monoisotopic mass	109.05276385 g/mol
SMILES	Nc1ccc(O)cc1
InChIKey	PLIKAWJENQZMHA-UHFFFAOYSA-N
PubChem CID	403
ChEMBL	CHEMBL1142
ChEBI	CHEBI:17602
EC No.	204-616-2
DTXSID	DTXSID3024499

Chemical & Physical Properties

XLogP	0
Topological polar surface area	46.3
Hydrogen bond donors	2
Hydrogen bond acceptors	2
Rotatable bonds	0
Heavy atoms	8
Formal charge	0
Complexity	66
LogP (partition coefficient)	log Kow = 0.04 at pH 7.4
Density	4-Aminophenol crystals exist in two forms. The alpha form (from alcohol, water, or ethyl acetate) is the more stable and has an orthorhombic pyramidal structure, density 1.290 g/cu cm /alpha-4-Aminophenol/
Color/Form	Orthorhombic plates from waterWhite plates from waterColorless crystalsWhite or reddish yellow crystals turn violet on exposure to light
Solubility	less than 1 mg/mL at 73 °F (NTP, 1992)Solubility in water: 0.39% at 0 °C0.65% at 24 °C0.80% at 30 °Cin ethyl methyl ketone: 9.3% at 58.5 °Cin absolute ethanol: 4.5% at 0 °Cpractically insoluble in benzene and chloroformSlightly soluble in toluene, diethyl ether, ethanol, cold watersoluble in acetonitrile, ethyl acetate, acetone, hot watervery soluble in dimethylsulfoxide.Very soluble in ethanolinsoluble in benzene, chloroformslightly soluble in trifluoroacetic acidsoluble in alkaliesIn water, 1.6X10+3 mg/L at 20 °C16.0 mg/mLwater: slightly soluble1.5 g/100 mL (20 ºC)
Flash point	195 °C (383 °F) - closed cup189 °C
Boiling point	543 °F at 760 mmHg (Decomposes) (NTP, 1992)284 °C at 760 mm Hg, decomposes167 °C at 8.0 mm Hg150 °C at 3.0 mm Hg130.2 °C at 0.3 mm HgBP: Can be sublimed at 0.3 mm Hg and 110 °C without decomposition ... forms salts with acids and bases ... Deteriorates under the influence of air and light ... Commercial product usually pink ... MP of commercial product 186 °C187.5 °C
Decomposition	When heated to decomposition it emits toxic fumes of /nitric oxides/.284 °C
Melting point	367 to 369 °F (NTP, 1992)367-369 °F187.5 °C187.50 °C. @ 760.00 mm Hg188 °C
Vapor pressure	0.00004 [mmHg]4.0X10-5 mm Hg at 25 °C0.4 hPa (110 °C)
Physical Description	P-aminophenol appears as white or reddish-yellow crystals or light brown powder. Turns violet when exposed to light. (NTP, 1992)Dry PowderWhite or reddish-yellow crystals or light-brown powder that turns violet when exposed to light[CAMEO]Solid
Stability/Shelf Life	Deteriorates under influence of air and light
Ionization Efficiency	Positive2.562.7Agilent XCTElectrospray ionizationformic acid (5.3nM)
Refractive index	1.5444 (estimate)
Storage conditions	2-8°C
Physical state	Crystalline Powder
pKa (acidity coefficient)	5.48, 10.30(at 25℃)
Color	White to cream
Sensitivity	Air & Light Sensitive
Merck	14,462
BRN	385836
Henry's law constant	2.7×104 mol/(m3Pa) at 25℃, Duchowicz et al. (2020)
Stability	Stable, though may discolour in air. Incompatible with acids, chloroformates, strong oxidizing agents.
Cosmetics Ingredients Functions	HAIR DYEING
Cosmetic Ingredient Review (CIR)	4-Aminophenol (123-30-8)
InChI	1S/C6H7NO/c7-5-1-3-6(8)4-2-5/h1-4,8H,7H2
InChIKey	PLIKAWJENQZMHA-UHFFFAOYSA-N
SMILES	Nc1ccc(O)cc1
LogP (partition coefficient)	-0.09-0.04 at 25℃
CAS DataBase Reference	123-30-8(CAS DataBase Reference)
EWG's Food Scores	4-6
FDA UNII	R7P8FRP05V
NIST Chemistry Reference	Phenol, 4-amino-(123-30-8)
EPA Substance Registry System	p-Aminophenol (123-30-8)
UNSPSC Code	41116107
NACRES	NA.24
GHS pictogram	GHS07,GHS08,GHS09
Signal word	Danger
GHS hazard statements	H302+H332-H316-H320-H361-H370-H372-H317-H334-H341-H410
GHS precautionary statements	P501-P273-P272-P260-P270-P202-P201-P271-P264-P280-P284-P302+P352-P391-P342+P311-P337+P313-P305+P351+P338-P308+P311-P362+P364-P333+P313-P301+P312+P330-P304+P340+P312-P405
Target organs	Kidney
Personal protective equipment (PPE)	dust mask type N95 (US), Eyeshields, Faceshields, Gloves
Hazard symbols	Xn,N
Risk statements (R)	20/22-50/53-68-40-R68-R50/53-R20/22
Safety statements (S)	28-36/37-60-61-28A-S61-S60-S36/37-S28A
UN transport number	UN 2512 (AMINOPHENOLS (o-, m-, p-))
Water hazard class (WGK)	3
RTECS number	SJ5075000
F	8
Autoignition temperature	>250 °C
TSCA inventory status	TSCA listed
Hazard class	6.1Acute Tox. 4 InhalationAcute Tox. 4 OralAquatic Acute 1Aquatic Chronic 1Muta. 2Skin Sens. 1STOT RE 2
Packing group	III
Customs code	28402090
Storage class	6.1C - Combustible acute toxic Cat.3toxic compounds or compounds which causing chronic effects
Hazardous substances data	123-30-8(Hazardous Substances Data)
Toxicity	LD50 orally in Rabbit: 375 mg/kg LD50 dermal Rabbit > 10000 mg/kg
REACH registrations	Active
Limited quantities	5.0 kg (11 lbs) (solid)
Excepted quantities	Max Inner Pack (30g or 30ml) and Max Outer Pack (1Kg or 1L)

Safety & Regulations

GHS classification	WarningH302: Harmful if swallowed [Warning Acute toxicity, oral]H332: Harmful if inhaled [Warning Acute toxicity, inhalation]H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]P203, P261, P264, P270, P271, P273, P280, P301+P317, P304+P340, P317, P318, P330, P391, P405, and P501 (click each P-code to see the statement)
Regulatory information	Chemical: Phenol, 4-amino-Commission Regulation No 844/2012Phenol, 4-amino- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Phenol, 4-amino- are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)TP - indicates a substance that is the subject of a proposed TSCA section 4 test rule.Status: Active Update: 05-07-2021 https://echa.europa.eu/registration-dossier/-/registered-dossier/13807Status: Active Update: 30-04-2014 https://echa.europa.eu/registration-dossier/-/registered-dossier/6216Status: Active Update: 16-05-2013 https://echa.europa.eu/registration-dossier/-/registered-dossier/64074-Aminophenol: Does not have an individual approval but may be used under an appropriate group standard
Other safety information	IMAP assessments - Phenol, 4-amino-: Human health tier II assessment
DOT label	Poison
Fire hazards	Flash point data are not available for this chemical. It is probably combustible. (NTP, 1992)
Health hazards	SYMPTOMS: Symptoms of exposure to this chemical may include asthma, irritation of the skin and eyes, dermatitis and methemoglobinemia with cyanosis.ACUTE/CHRONIC HAZARDS: This compound is a skin and eye irritant and an allergen. When heated to decomposition it emits toxic fumes. (NTP, 1992)

Applications & Uses

Uses

4-Aminophenol is widely used in the synthesis of pharmaceuticals, dyes and other organic products and is mainly for the synthesis of paracetamol, clofibrate ketone, vitamin B1 and compound nicotinamide. It can be used for the production of Sulphur Blue FBG and weak acid dyes such as yellow 5G.The product is the intermediate of pharmaceutical intermediates, dyes and other fine chemicals. It can be used for the production of paracetamol, azo dyes, sulfur dyes, acid dyes, fur dye and developer, antioxidants as well as oil additive.It can be used for gold assay as well as determination of copper, iron, magnesium, vanadium, nitrite and cyanate, antioxidants.p-Aminophenol is an oxidative hair dye precursor. It is incorporated in oxidative hair dye formulations and in the bottle on the market at a maximum concentration of 1.8% and is typically mixed in a 1:1 ratio with an oxidative agent thereby reaching a concentration of 0.9% for in use application.

Description

4-Aminophenol, also known as 4-hydroxyaniline, is an organic building block. Its quantification in water samples upto the detection limit of 8×10-10mol l-1 has been proposed by employing single-wall carbon nanotubes (SWNT)-nafion film coated glassy carbon electrodes. It is present as the main contaminant in pharmaceutical formulations of paracetamol. High-performance liquid chromatographic (HPLC) method with amperometric detection has been reported for its determination in various analgesic formulations. It has been reported to be formed from the reduction of 4-nitrophenol (Nip) under metal-free conditions catalyzed by N-doped graphene (NG).

Uses

4-Aminophenol is suitable for use in the synthesis of 2,2-bis(4-aminophenoxy) benzonitrile [4-APBN], a monomer required for the preparation of series of polyamides and poly(amide-imide)s. It may be used as derivatization reagent to improve the ionization of aliphatic and aromatic aldehydes by paper spray ionization mass spectrometry.

General Description

P-aminophenol appears as white or reddish-yellow crystals or light brown powder. Turns violet when exposed to light. (NTP, 1992)

Preparation & Synthesis

Preparation

5 g of phenylhydroxylamine are slowly added to 100 ml of 50% sulphuric acid, cooled in a freezing mixture, 500 ml of water poured in, and the whole boiled until a sample, tested with chromic acid solution, gives a smell of quinone and no smell of nitrobenzene. The liquid is neutralised with sodium bicarbonate, saturated with common salt, and extracted with ether. The ether is removed by evaporation, and the residue washed with cold water and dissolved in hot water. The solution is filtered hot, and cooled, and the 4-aminophenol again extracted with ether. Yield almost theoretical. Colourless crystals; somewhat soluble in water; m.p. 185° C.Systematic organic chemistry, by W. M. Cumming, 209, 1937.

Preparation

Conventionally 4-aminophenol was manufactured using iron-acid reduction of p-nitrobenzene. Reduction using iron-acid is a multi-step process. The modern method is the catalytic dehydrogenation of nitrobenzene to 4-aminophenol using a noble metal catalyst in the presence of an acidic medium. This method also produces aniline as a side-product. The advantage of a reduction using a noble metal catalyst is that it involves a single step reaction, an environment friendly and more efficient process, as there is no evolution of an environmentally harmful gas. Moreover, the side-product aniline is also a valuable chemical.synthesis of 4-aminophenol