Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and 2-Naphthol: Difference between pages

{{use dmy dates|date=November 2022}}

| Watchedfields = changed

| verifiedrevid = 477214746

| ImageFile = Beta-Naphthol.svg

| ImageSize = 180px

| ImageFile1 = 2-Naphthol-3D-balls.png

| ImageSize1 = 180px

| ImageFile2 = Β-Naphthol.jpg

| ImageSize2 = 220px

| PIN=Naphthalen-2-ol

| OtherNames=2-Hydroxynaphthalene; 2-Naphthalenol; ''beta''-Naphthol; Naphth-2-ol

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo=135-19-3

| Beilstein = 742134

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 10432

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 14126

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 8341

| EC_number = 205-182-7

| Gmelin = 27395

| PubChem=8663

| RTECS = QL2975000

| UNNumber = 3077

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = P2Z71CIK5H

| SMILES = Oc2ccc1c(cccc1)c2

| SMILES1 = c1ccc2cc(ccc2c1)O

| 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

| MainHazards= [[Harmful]] when inhaled or swallowed; dangerous to environment, esp. aquatic organisms.<ref name="msds">{{Cite web |title=MSDS safety data for 2-naphthol |url=https:https://msds.chem.ox.ac.uk/NA/2-naphthol.html |url-status=dead |archive-url=https://web.archive.org/web/20110303133020/https://msds.chem.ox.ac.uk/NA/2-naphthol.html |df=dmy-all |archive-date=2011-03-03}}</ref>

| FlashPtC = 161

| FlashPt_ref = <ref name="msds" />

| AutoignitionPtC =

| NFPA-H = 2

| NFPA-F = 1

| NFPA-R = 0

| GHSPictograms = {{GHS07}} {{GHS09}}

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|302|332|400}}

| PPhrases = {{P-phrases|261|264|270|271|273|301+312|304+312|304+340|312|330|391|501}}

'''2-Naphthol''', or '''β-naphthol''', is a [[fluorescence|fluorescent]] colorless (or occasionally yellow) crystalline solid with the formula C₁₀H₇OH. It is an [[isomer]] of [[1-Naphthol|1-naphthol]], differing by the location of the [[hydroxide|hydroxyl group]] on the [[naphthalene]] ring. The naphthols are naphthalene homologues of [[phenol]], but more reactive. Both isomers are soluble in simple [[Alcohol (chemistry)|alcohol]]s, [[ether]]s, and [[chloroform]]. 2-Naphthol is a widely used intermediate for the production of [[dye]]s and other compounds.

==Production==

Traditionally, 2-naphthol is produced by a two-step process that begins with the [[sulfonation]] of naphthalene in [[sulfuric acid]]:<ref name=Ullmann>{{Ullmann|first=Gerald|last=Booth|title=Naphthalene Derivatives|year=2005|doi=10.1002/14356007.a17_009}}. [https://pdfslide.net/documents/ullmanns-encyclopedia-of-industrial-chemistry-naphthalene-derivatives.html '''full-text PDF''']</ref>

: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]].<ref name=Ullmann/>

==2-Naphthol-derived dyes==

The [[Sudan dye]]s are popular dyes noted for being soluble in organic solvents. Several of the Sudan dyes are derived from 2-naphthol by coupling with [[diazonium salt]]s.<ref name="Ullmann's Encyclopedia of Industrial Chemistry">{{cite book|last1=Booth|first1=Gerald|first2=Heinrich|last2=Zollinger|first3=Keith|last3=McLaren|first4=William G.|last4=Sharples|first5=Alan|last5=Westwell|year=2000|publisher=[[Wiley-VCH]]|doi=10.1002/14356007.a09_073|title=Ullmann's Encyclopedia of Industrial Chemistry|isbn=9783527306732|chapter=Dyes, General Survey}}</ref> Sudan dyes I–IV and Sudan Red G consist of [[diazonium salt|arylazo]]-substituted [[naphthol]]s.

<gallery caption="Selected 2-Naphthol-derived dyes" widths="180px" heights="120px" perrow="4">

File:Sudan I.svg|[[Sudan I]]

File:Sudan II.svg|[[Sudan II]]

File:Sudan III.svg|[[Sudan III]]

File:Sudan IV.svg|[[Sudan IV]]

File:Oil Red O.svg|[[Oil Red O]]

File:Naphthol AS.svg|[[Naphthol AS]]

</gallery>

==Reactions==

Some reactions of 2-naphthol are explicable with reference to its tautomerism, which produces a small amount of the keto tautomer.

:[[File:Beta-naphthol tautomerism.svg|thumb|Tautomeric equilibrium for beta-naphthol|left|384px]]

One consequence of this tautomerism is the [[Bucherer reaction]], the ammonolysis of 2-naphthol to give [[2-aminonaphthalene]].

2-Naphthol can be oxidatively coupled to form [[1,1'-bi-2-naphthol|BINOL]], a [[C2-Symmetric ligands|''C''₂-symmetric ligand]] popularized for use in [[asymmetric catalysis]].

[[File:CuCl2 naphthol coupling.png|400px|left|''Coupling of beta-naphthol using CuCl2'']]{{clear left}}

2-Naphthol converts to [[2-Naphthalenethiol|2-naphthalenethiol]] by reaction with [[dimethylthiocarbamoyl chloride]] via the [[Newman–Kwart rearrangement]].<ref>{{cite journal|title=Thiophenols from Phenols: 2-Naphthalenethiol|author1=Melvin S. Newman |author2=Frederick W. Hetzel|url=https://www.orgsyn.org/demo.aspx?prep=CV6P0824 |journal=[[Organic Syntheses]]|year=1971|volume=51|page=139|doi=10.15227/orgsyn.051.0139}}</ref> The OH→Br conversion has been described.<ref>{{cite journal |doi=10.15227/orgsyn.049.0006|title=2-Bromonaphthalene |journal=Organic Syntheses |year=1969 |volume=49 |page=6 |author1=J. P. Schaefer|author2=Jerry Higgins|author3=P. K. Shenoy }}</ref>

Electrophilic attack occurs characteristically at the 1-position as indicated by [[nitrosylation]] to give [[1-Nitroso-2-naphthol|1-nitroso-2-naphthol]].<ref>{{cite journal |doi=10.15227/orgsyn.002.0061|journal=Organic Syntheses |year=1922 |volume=2 |page=61 |title=Nitroso-β-Naphthol |first1=C. S.|last1=Marvel|first2=P. K.| last2=Porter}}</ref> Bromination<ref>{{cite journal |doi=10.15227/orgsyn.020.0018|title=6-Bromo-2-Naphthol |journal=Organic Syntheses |year=1940 |volume=20 |page=18 |author=C. Frederick Koelsch }}</ref> and alkylations proceed with similar regiochemistry.<ref>{{cite journal |doi=10.15227/orgsyn.022.0063|title=2-Hydroxy-1-Naphthaldehyde |journal=Organic Syntheses |year=1942 |volume=22 |page=63|author=Alfred Russell Luther B. Lockhart }}</ref> Ring-opening reactions have been documented.<ref>{{cite journal |doi=10.15227/orgsyn.034.0008 |journal=Organic Syntheses |year=1954 |volume=34 |page=8|title=β-(o-Carboxyphenyl)propionic Acid |author=G. A. Page, D. S. Tarbell }}</ref>

Carbonation of 2-naphthol gives [[2-Hydroxy-1-naphthoic acid|2-hydroxy-1-naphthoic acid]].<ref name=Ullmann/>

==Safety==

2-Naphthol has been described as "moderately toxic.<ref name=Ullmann/>

== References ==

{{Reflist}}

== External links ==

* [https://webbook.nist.gov/cgi/cbook.cgi?Name=2-naphthol&Units=SI NIST Chemistry WebBook 2-Naphthalenol]

* {{cite EB1911 |wstitle=Napthols |volume=19 |pages=168–169 |short=1}}

{{DEFAULTSORT:Naphthol, 2-}}

[[Category:2-Naphthols| ]]

[[Category:2-Naphthyl compounds]]