2-Aminophenol

Last updated
2-Aminophenol
O-Aminophenol.svg
Space filling model of 2-aminophenol 2-aminophenol-space-filling.png
Space filling model of 2-aminophenol
Ball-and-stick model of 2-aminophenol 2-aminophenol-ball-and-stick.png
Ball-and-stick model of 2-aminophenol
Names
Preferred IUPAC name
2-Aminophenol [1]
Other names
o-Aminophenol
ortho-Aminophenol
2-Hydroxyaniline
2-Amino-1-hydroxybenzene
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.002.211 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 202-431-1
KEGG
PubChem CID
RTECS number
  • SJ4950000
UNII
UN number 2512
  • InChI=1S/C6H7NO/c7-5-3-1-2-4-6(5)8/h1-4,8H,7H2 Yes check.svgY
    Key: CDAWCLOXVUBKRW-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C6H7NO/c7-5-3-1-2-4-6(5)8/h1-4,8H,7H2
    Key: CDAWCLOXVUBKRW-UHFFFAOYAP
  • Oc1ccccc1N
Properties
C6H7NO
Molar mass 109.13 g/mol
AppearanceWhite orthorhombic pyramidal needles
Density 1.328 g/cm3
Melting point 174 °C (345 °F; 447 K)
slightly soluble in cold water, soluble in hot water
Acidity (pKa)
  • 4.78 (amino; 20 °C, H2O)
  • 9.97 (phenol; 20 °C, H2O) [2]
Hazards
GHS labelling:
GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg
Warning
H302, H332, H341
P201, P202, P261, P264, P270, P271, P281, P301+P312, P304+P312, P304+P340, P308+P313, P312, P330, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

2-Aminophenol is an organic compound with the formula C6H7NO. Along with its isomer 4-aminophenol, it is an amphoteric molecule and a reducing agent. It is a useful reagent for the synthesis of dyes and heterocyclic compounds. [3] Reflecting its slight hydrophilic character, white powder is moderately soluble in alcohols and can be recrystallized from hot water.

Contents

Synthesis and structure

2-Aminophenol (and its isomer, 4-aminophenol) is industrially synthesized by reducing the corresponding nitrophenol by hydrogen in the presence of various catalysts. The nitrophenols can also be reduced with iron. [3]

The compound exhibits intra- and intermolecular hydrogen bonding involving the neighbouring amine and hydroxyl groups. As a result, 2-aminophenol has a relatively high melting point (174 °C) compared to other compounds with a similar molecular mass; for example, 2-methylphenol melts at 31 °C. [4]

Applications

2-Aminophenol has a variety of uses. As a reducing agent, it is marketed under the names of Atomal and Ortol to develop black-and-white photographs. [3] 2-Aminophenol is an intermediate in the synthesis of dyes. It is particularly useful in yielding metal-complex dyes when diazotized and coupled to a phenol, naphthol, or other aromatic or resonant dye species. Metal complex dyes using copper or chromium are commonly used for producing dull colors. Tridentate ligand dyes are useful because they are more stable than their bi- or mono-dentate counterparts. [5] [6]

2-aminophenol diaz coup.png
2-aminophenol coord.png

Due to the adjacency of the amino and hydroxyl groups, 2-aminophenol readily forms heterocycles. These heterocycles, such as benzoxazoles, can be biologically active and useful in the pharmaceutical industry: [3]

2-aminophenol cyclization.png

Related Research Articles

<span class="mw-page-title-main">Acridine</span> Chemical compound

Acridine is an organic compound and a nitrogen heterocycle with the formula C13H9N. Acridines are substituted derivatives of the parent ring. It is a planar molecule that is structurally related to anthracene with one of the central CH groups replaced by nitrogen. Like the related molecules pyridine and quinoline, acridine is mildly basic. It is an almost colorless solid, which crystallizes in needles. There are few commercial applications of acridines; at one time acridine dyes were popular, but they are now relegated to niche applications, such as with acridine orange. The name is a reference to the acrid odour and acrid skin-irritating effect of the compound.

1-Hexanol (IUPAC name hexan-1-ol) is an organic alcohol with a six-carbon chain and a condensed structural formula of CH3(CH2)5OH. This colorless liquid is slightly soluble in water, but miscible with diethyl ether and ethanol. Two additional straight chain isomers of 1-hexanol, 2-hexanol and 3-hexanol, exist, both of which differing by the location of the hydroxyl group. Many isomeric alcohols have the formula C6H13OH. It is used in the perfume industry.

<span class="mw-page-title-main">Acenaphthene</span> Chemical compound

Acenaphthene is a polycyclic aromatic hydrocarbon (PAH) consisting of naphthalene with an ethylene bridge connecting positions 1 and 8. It is a colourless solid. Coal tar consists of about 0.3% of this compound.

In organic chemistry, dihydroxybenzenes (benzenediols) are organic compounds in which two hydroxyl groups are substituted onto a benzene ring. These aromatic compounds are classed as phenols. There are three structural isomers: 1,2-dihydroxybenzene is commonly known as catechol, 1,3-dihydroxybenzene is commonly known as resorcinol, and 1,4-dihydroxybenzene is commonly known as hydroquinone.

<span class="mw-page-title-main">Sulfonic acid</span> Organic compounds with the structure R−S(=O)2−OH

In organic chemistry, sulfonic acid refers to a member of the class of organosulfur compounds with the general formula R−S(=O)2−OH, where R is an organic alkyl or aryl group and the S(=O)2(OH) group a sulfonyl hydroxide. As a substituent, it is known as a sulfo group. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound is the parent sulfonic acid, HS(=O)2(OH), a tautomer of sulfurous acid, S(=O)(OH)2. Salts or esters of sulfonic acids are called sulfonates.

In organic chemistry a halohydrin is a functional group in which a halogen and a hydroxyl are bonded to adjacent carbon atoms, which otherwise bear only hydrogen or hydrocarbyl groups. The term only applies to saturated motifs, as such compounds like 2-chlorophenol would not normally be considered halohydrins. Megatons of some chlorohydrins, e.g. propylene chlorohydrin, are produced annually as precursors to polymers.

<span class="mw-page-title-main">Triazine</span> Aromatic, heterocyclic compound

Triazines are a class of nitrogen-containing heterocycles. The parent molecules' molecular formula is C3H3N3. They exist in three isomeric forms, 1,3,5-triazines being common.

<span class="mw-page-title-main">Cyanuric chloride</span> Chemical compound

Cyanuric chloride is an organic compound with the formula (NCCl)3. This white solid is the chlorinated derivative of 1,3,5-triazine. It is the trimer of cyanogen chloride. Cyanuric chloride is the main precursor to the popular but controversial herbicide atrazine.

Xylenols are organic compounds with the formula (CH3)2C6H3OH. They are volatile colorless solids or oily liquids. They are derivatives of phenol with two methyl groups at various positions relative to the hydroxyl group. Six isomers exist, of which 2,6-xylenol with both methyl groups in an ortho position with respect to the hydroxyl group is the most important. The name xylenol is a portmanteau of the words xylene and phenol.

Nitrophenols are compounds of the formula HOC6H5−x(NO2)x. The conjugate bases are called nitrophenolates. Nitrophenols are more acidic than phenol itself.

<span class="mw-page-title-main">Oxazines</span> E heterocyclic organic compounds containing one oxygen and one nitrogen atom

Oxazines are heterocyclic organic compounds containing one oxygen and one nitrogen atom in a cyclohexa-1,4-diene ring. Isomers exist depending on the relative position of the heteroatoms and relative position of the double bonds.

<span class="mw-page-title-main">4-Aminophenol</span> Chemical compound

4-Aminophenol (or para-aminophenol or p-aminophenol) is an organic compound with the formula H2NC6H4OH. Typically available as a white powder, it is commonly used as a developer for black-and-white film, marketed under the name Rodinal.

3-Aminophenol is an organic compound with formula C6H4(NH2)(OH). It is an aromatic amine and a phenol. It is the meta isomer of 2-aminophenol and 4-aminophenol.

In chemistry, carbonylation refers to reactions that introduce carbon monoxide (CO) into organic and inorganic substrates. Carbon monoxide is abundantly available and conveniently reactive, so it is widely used as a reactant in industrial chemistry. The term carbonylation also refers to oxidation of protein side chains.

<span class="mw-page-title-main">2-Nitrobenzaldehyde</span> Chemical compound

2-Nitrobenzaldehyde is an organic compound with the formula O2NC6H4CHO. It is one of three isomers of nitrobenzaldehyde. It contains a nitro group adjacent to the formyl group.

<span class="mw-page-title-main">1,4-Dihydroxyanthraquinone</span> Chemical compound

1,4-Dihydroxyanthraquinone, also called quinizarin or Solvent Orange 86, is an organic compound derived from anthroquinone. Quinizarin is an orange or red-brown crystalline powder. It is formally derived from anthraquinone by replacement of two hydrogen atoms by hydroxyl (OH) groups. It is one of ten dihydroxyanthraquinone isomers and occurs in small amounts in the root of the madder plant, Rubia tinctorum.

A tetrahydroxyanthraquinone, also called tetrahydroxyanthradione, is any of several isomeric organic compounds with formula (C12H44)(CO)2, almost invariably derived from 9,10-anthraquinone by replacing four hydrogen atoms by hydroxyl groups. Only a few of these isomers are commercially significant. These are 1,2,5,8-tetrahydroxyanthraquinone (quinalizarin), 1,4,5,8-tetrahydroxyanthraquinone, and 1,2,3,4-tetrahydroxyanthraquinone.

4-Nitrotoluene or para-nitrotoluene is an organic compound with the formula CH3C6H4NO2. It is a pale yellow solid. It is one of three isomers of nitrotoluene.

<span class="mw-page-title-main">1,4-Dichloro-2-nitrobenzene</span> Chemical compound

1,4-Dichloro-2-nitrobenzene is an organic compound with the formula C6H3Cl2NO2. One of several isomers of dichloronitrobenzene, it is a yellow solid that is insoluble in water. It is produced by nitration of 1,4-dichlorobenzene. It is a precursor to many derivatives of commercial interest. Hydrogenation gives 1,4-dichloroaniline. Nucleophiles displace the chloride adjacent to the nitro group: ammonia gives the aniline derivative, aqueous base gives the phenol derivative, and methoxide gives the anisole derivative. These compounds are respectively 4-chloro-2-nitroaniline, 4-chloro-2-nitrophenol, and 4-chloro-2-nitroanisole.

<span class="mw-page-title-main">2,5-Dichloroaniline</span> Chemical compound

2,5-Dichloroaniline is an organic compound with the formula C6H3Cl2NH2. One of six isomers of dichloroaniline, it is a colorless solid that is insoluble in water. It is produced by hydrogenation of 1,4-dichloro-2-nitrobenzene. It is a precursor to dyes and pigments, e.g., Pigment Yellow 10.

References

  1. ↑ Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 690. doi:10.1039/9781849733069-FP001. ISBN   978-0-85404-182-4.
  2. ↑ Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. p. 5–89. ISBN   978-1498754286.
  3. 1 2 3 4 Mitchell, S.C. & Waring, R.H. "Aminophenols." In Ullmann’s Encyclopedia of Industrial Chemistry; 2002 Wiley-VCH, doi : 10.1002/14356007.a02_099.
  4. ↑ Reference Handbook of Fine Chemicals, Acros Organics Publishers, Fisher Scientific UK, (2007), www.acros.com
  5. ↑ Grychtol, K.; Mennicke, W. "Metal-Complex Dyes." In Ullmann’s Encyclopedia of Industrial Chemistry; 2002, Wiley-VCH, doi : 10.1002/14356007.a16_299
  6. ↑ Hunger, K.; Mischke, P.; Rieper, W.; Raue, R.; Kunde, K.; Engel, A. "Azo Dyes." In Ullmann’s Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, doi : 10.1002/14356007.a03_245
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.