“2-Naphthol”的意思、由来-开放百科全书

词条

2-Naphthol

释义

Production
2-Naphthol-derived dyes
Reactions
Safety
References
External links

{{chembox
| Watchedfields = changed
| verifiedrevid = 477214746
| ImageFile = Beta-Naphthol.svg
| ImageSize = 180px
| ImageFile1 = 2-Naphthol-3D-balls.png
| ImageSize1 = 180px
| ImageFile2 = Β-Naphthol.jpg
| ImageSize2 = 220px
| IUPACName=Naphthalen-2-ol
| OtherNames=2-Hydroxynaphthalene; 2-Naphthalenol; beta-Naphthol; Naphth-2-ol
|Section1={{Chembox Identifiers
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = P2Z71CIK5H
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C11713
| InChI = 1/C10H8O/c11-10-6-5-8-3-1-2-4-9(8)7-10/h1-7,11H
| InChIKey = JWAZRIHNYRIHIV-UHFFFAOYAV
| SMILES1 = c1ccc2cc(ccc2c1)O
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 14126
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C10H8O/c11-10-6-5-8-3-1-2-4-9(8)7-10/h1-7,11H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = JWAZRIHNYRIHIV-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo=135-19-3
| PubChem=8663
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 10432
| SMILES = Oc2ccc1c(cccc1)c2
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8341
|Section2={{Chembox Properties
| C=10 | H=8 | O=1
| Appearance=Colorless crystalline solid
| Density=1.280 g/cm³
| MeltingPtC = 121 to 123
| BoilingPtC = 285
| Solubility=0.74 g/L
| pKa = 9.51
| MagSus = -98.25·10⁻⁶ cm³/mol
|Section3={{Chembox Hazards
| MainHazards= Harmful when inhaled or swallowed; dangerous to environment, esp. aquatic organisms.^[1]
| FlashPt = {{convert|161|C|F}}^[1]
| AutoignitionPtC =
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| RPhrases = {{R20}} {{R22}} {{R50}}
| SPhrases = {{S24}} {{S25}} {{S61}}
}}

2-Naphthol, or β-naphthol, is a fluorescent colorless (or occasionally yellow) crystalline solid with the formula C₁₀H₇OH. It is an isomer of 1-naphthol, differing by the location of the hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol, but more reactive. Both isomers are soluble in simple alcohols, ethers, and chloroform. 2-Naphthol is a widely used intermediate for the production of dyes and other compounds.

Production

Traditionally, 2-naphthol is produced by a two-step process that begins with the sulfonation of naphthalene in sulfuric acid:^[2]

C₁₀H₈ + H₂SO₄ → C₁₀H₇SO₃H + H₂O

The sulfonic acid group is then cleaved in molten sodium hydroxide:

C₁₀H₇(SO₃H) + 3 NaOH → C₁₀H₇ONa + Na₂SO₃ + 2 H₂O

Neutralization of the product with acid gives 2-naphthol.

2-Naphthol can also be produced by a method analogous to the cumene process.^[2]

2-Naphthol-derived dyes

The Sudan dyes are popular dyes noted for being soluble in organic solvents. Several of the Sudan dyes are derived from 2-naphthol by coupling with diazonium salts.^[3] Sudan dyes I -IV and Sudan Red G consist of arylazo-substituted naphthols.

Reactions

2-Naphthol reacts to form BINOL, a C2-symmetric ligand popularized for use in asymmetric catalysis.

2-Naphthol converts to 2-naphthalenethiol via reaction with dimethylthiocarbamoyl chloride via the Newman-Kwart rearrangement.^[4]

Safety

Naphthols (both 1 and 2 isomers) are used as biomarkers for livestock and humans exposed to polycyclic aromatic hydrocarbons.^[5]

References

1. ^¹Safety data for 2-naphthol
2. ^¹Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a17_009}}.
3. ^{{cite book|last=Booth|first=Gerald|year=2000|publisher=Wiley-VCH |doi=10.1002/14356007.a09_073|title=Ullmann's Encyclopedia of Industrial Chemistry|isbn=978-3527306732|chapter=Dyes, General Survey}}
4. ^{{cite journal|title=Thiophenols from Phenols: 2-Naphthalenethiol|authors=Melvin S. Newman, Frederick W. Hetzel|journal=Org. Synth.|year=1971|volume=51|page=139|doi=10.15227/orgsyn.051.0139}}
5. ^{{cite journal|last=Sreekanth|first=R.|author2=Prasanthkumar, Kavanal P.|author3=Sunil Paul, M. M.|author4=Aravind, Usha K.|author5=Aravindakumar, C. T.|title=Oxidation Reactions of 1- and 2-Naphthols: An Experimental and Theoretical Study|journal=The Journal of Physical Chemistry A|date=7 November 2013|volume=117|issue=44|pages=11261–11270|doi=10.1021/jp4081355|pmid=24093754}}

External links

NIST Chemistry WebBook 2-Naphthalenol

1 : 2-Naphthols

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