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EC / List no.: 205-182-7
CAS no.: 135-19-3
Mol. formula: C10H8O
Beta Naphthol, or β-naphthol, is a fluorescent colorless (or occasionally yellow) crystalline solid with the formula C10H7OH.
Beta Naphthol 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.
Beta Naphthol is a widely used intermediate for the production of dyes and other compounds.
Production
Traditionally, Beta Naphthol is produced by a two-step process that begins with the sulfonation of naphthalene in sulfuric acid:
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 Beta Naphthol.
Beta Naphthol can also be produced by a method analogous to the cumene process.
Beta Naphthol derived dyes
The Sudan dyes are popular dyes noted for being soluble in organic solvents. Several of the Sudan dyes are derived from Beta Naphthol by coupling with diazonium salts.
Sudan dyes I -IV and Sudan Red G consist of arylazo-substituted naphthols.
Reactions
Beta Naphthol reacts to form BINOL, a C2-symmetric ligand popularized for use in asymmetric catalysis.
Beta Naphthol converts to 2-naphthalenethiol via reaction with dimethylthiocarbamoyl chloride via the Newman-Kwart rearrangement.
Chemical Properties
White lustrous leaflets or white powder.
Insoluble in water, soluble in ethanol, ether, chloroform, glycerol, and alkaline solutions.
Application
Beta Naphthol is used to produce Tobias acid, J acid, 2-hydroxy-3-naphthoic acid and azo dyes, and it is the raw material for rubber antioxidants, mineral dressing agents, fungicides, antiseptics, preservatives, etc.
As feed preservative.
In China, it can be used for citrus preservation, the maximum dosage amount is 0.1 g/kg and the residue amount should be no more than 70 mg/kg.
Beta Naphthol, also called ß-naphthol, 2-naphthalenol, is the intermediate for plant growth regulator, 2-naphthoxyacetic acid.
As analytic agent, absorbent of ethylene and carbon monoxide, and fluorescence indicator.
Important organic raw material and dye intermediate, used to produce Tobias acid, butyric acid, β-hydroxynaphthoic acid and used to produce N-phenyl-2-naphthylamine, Diafen NN and other antioxidant, organic pigments, and fungicides.
For the detection of bromine, chlorine, chlorate, niobium, copper, nitrite, and potassium. Substrate for fluorometric assay of phenol sulfotransferase.
Acid and alkali indicator, dyes, organic synthesis, qualitative determination of allyl alcohol, methanol, chloroform, etc.
Absorbent of carbon monoxide, ethanol, and fluorescence indicator. Determination of carbon monoxide, copper, nitrite, and potassium. Ethylene absorbent.
Preparation
(1) Sulfonation alkali melting method
Obtained by sulfonation of naphthalene and alkali melting.
Sulfonation alkali melting Beta Naphthol synthesis process is widely used in both domestic and foreign production, but it is with serious corrosion, high cost, large amount of waste water and high biological oxygen consumption.
American Cyanamid Company developed 2-isopropyl-naphthalene method with naphthalene and propylene as the raw materials, which produces Beta Naphthol and with byproduct acetone.
This method is similar to Cumene process to produce phenol.
The consumed amount of raw materials: 1170 kg/t refined naphthalene, 1080 kg/t sulfuric acid, 700 kg/t sodium hydroxide (caustic soda).
Details: Refined naphthalene was put into the sulfonation kettle and heated up to 140°C (melting).
Sulfuric acid (sulfuric acid/refined naphthalene (mol/mol=1.8) was added within 20 minutes.
The temperature was raised up to 160-164°C and kept for 2.5 h.
The reaction was terminated when the content of 2-naphthalenesulfonic acid is above 66% and the total acidity is 25%-27%.
The sulfonates were hydrolyzed for 1 h at 140-150°C inside a hydrolysis kettle.
Following neutralization at 80-90°C with sodium nitrite solution was performed until the Congo red test paper was no more blue.
Steam and air were used to remove SO2 gas.
When the temperature was cooled down to 30-40°C, vacuum filtration was applied.
After washing with salt water (10%) and following vacuum filtration, 2-naphthalenesulfonic acid sodium salt was obtained.
Sodium hydroxide was put into an alkali melting kettle and heated to 290°C (melting).
At about 3 hours 2-naphthalenesulfonic acid sodium salt was added until the freebase content was 5%-6%.
Afterwards, the temperature was kept at 320-330°C for 1 hour.
The alkali melt was diluted with water and SO2 gas was passed at 70-80°C until phenolphthalein did not show any color.
Addition of water to boil and wash, sodium sulfite was removed, dehydration and then under reduced pressure to distill the final product.
The total yield is 73%-74%.
(2) 2-isopropyl-naphthalene method.
With naphthalene and ethylene as the raw materials to produce 2-naphthaol with byproduct acetone.
Details: Sulfuric acid was added into the melted naphthalene at 140℃ and the sulfonation was carried out at 162-164°C.
The sulfonates were hydrolyzed, the free naphthalene was blown away and sodium sulfite was added to react and generate 2-naphthalenesulfonic acid sodium salt.
This salt together with sodium hydroxide were alkali melted at 285-320°C and kept at 320-330°C for 1 hour.
After the dilution of this alkali melt, acidification with SO2 gas was performed to obtain crude products.
Followed washing, dehydration and distillation were carried out to obtain the final products.
Chemical Properties
white or off-white powder with a slight
Beta Naphthol is a white, crystalline solid. Slight phenolic odor. Darkens in air and on exposure to light.
Uses:
Has been used as antiseptic, anthelmintic and counter-irritant in alopecia.
anthelmintic, antiseptic
Beta Naphthol is used in the manufacture of dyes, perfumes, and medicinal organics, and in the production of antioxidants for synthetic rubber.
Preparation
products were made Naphthalen-2-ol, and sodium hydroxide melting, finally using hydrochloric acid or carbon dioxide exhalation.
Definition
ChEBI: A naphthol carrying a hydroxy group at position 2.
Properties and Applications
white crystalline, with phenol smell. Industrial goods for hoar chip or powder.
Melting point 121 ~ 123 ℃, 285 ℃ ~ 286 boiling point, flash point 161 ℃.
This product soluble in water, ethanol, ethyl ether, chloroform, glycerin and alkali solution, can the sublimation, with steam evaporate out; Long storage or light color in turn dark, can happen oxidation, reduction, nitrification and nitrosation reaction, and products, light and heat, halogenating role, etc.
Purification Methods
Crystallise Beta Naphthol from aqueous 25% EtOH (charcoal), H2O, *benzene, toluene or CCl4.
Alternatively, extract it repeatedly with small amounts of EtOH, followed by dissolution in a minimum volume of EtOH and precipitation with distilled water, then drying over P2O5 under vacuum. Beta Naphthol has also been dissolved in aqueous NaOH and precipitated by adding acid (repeat several times), then precipitated from *benzene by addition of heptane.
Final purification can be by zone melting or sublimation in vacuo.
The 4-nitrobenzoate has m 104o (from EtOH).
Incompatibilities
Dust or powder may form explosive mixture with air.
Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions.
Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides, iron salts; 2,3-dimethyl-1- phenyl-3-pyrazolin-5-one (antipyrine); camphor, phenol, menthol, urethane.
Beta Naphthol is a naphthol carrying a hydroxy group at position 2.
Beta Naphthol has a role as an antinematodal drug, a genotoxin, a human xenobiotic metabolite, a mouse metabolite, a human urinary metabolite and a radical scavenger.
Use and Manufacturing
The principal uses for 2-naphthalenol are in the dyes and pigments industries, eg, as a coupling component for azo dyes, and to make important intermediates, such as 3-hydroxy-2-naphthalenecarboxylic acid (BON) and its anilide (naphthol AS), 2-naphtholsulfonic acids, aminonaphtholsulfonic acids, and 1-nitroso-2-naphthol.
Industry Uses
Dyes
Pigments
Consumer Uses
Agricultural products (non-pesticidal)
Ink, toner, and colorant products
Paints and coatings
Plastic and rubber products not covered elsewhere
Methods of Manufacturing
Beta Naphthol is produced by caustic fusion of naphthalene-2-sulfonic acid.
Typically, the sodium salt of the sulfonic acid is added gradually to 50% sodium hydroxide liquor at 300 °C; the melt is then heated further at 320 °C in a gas-fired iron vessel with vigorous agitation.
After completion of the reaction, the melt is run into excess water, possibly including filtrate from the previous batch at a proven tolerable level, and the naphtholate solution is neutralized to pH 8 with dilute sulfuric acid.
If the temperature is maintained at >100 °C during neutralization, the crude product comes out of solution as an oil, which is separated, washed with hot water, and distilled under vacuum to give pure Beta Naphthol.
The molten material is processed through a flaker to give the final product for packaging.
The fusion yield is about 80% of the theoretical value, resulting in an overall yield of 70% based on naphthalene.
Beta Naphthol undergoes three-component one-pot condensation reaction with ureas/amides and aldehydes catalyzed by sulfamic acid under ultrasound irradiation to give 1-amidoalkyl-2-naphthols.
Anodic oxidation of Beta Naphthol in acidic media has been investigated at a synthetic boron-doped diamond thin film electrode using cyclic voltammetry and bulk electrolysis.
Beta Naphthol is a colorless crystalline solid and an isomer of 1-naphthol, differing by the location of the hydroxyl group on naphthalene.
The naphthols are naphthalene homologues of phenol, with the hydroxyl group being more reactive than in the phenols.
Beta Naphthol has several different uses including dyes, pigments, fats, oils, insecticides, pharmaceuticals, perfumes, antiseptics, synthesis of fungicides, and antioxidants for rubber.
Detection of Beta Naphthol in urine usually results from long-term persistent exposure to pesticides such as chlorpyrifos, but also due to exposure to naphthalene in older types of mothballs, fires that produce polyaromatic hydrocarbons (PAHs), and tobacco smoke.
Beta-Naphthol violet exhibits antiseptic properties and is used in the synthesis of certain azo dyes and antioxidants for rubber.
Beta-Naphthol violet can also be used in the detection of the ferric ion which turns the Beta-Naphthol violet solution green.
Beta Naphthol can be used as a fluorescent indicator.
Beta Naphthol can be also used in the production of dyes and in organic synthesis.
Description
2-Naphthol (2-Hydroxynaphthalene, 2-Naphthalenol, beta-Naphthol, Naphth-2-ol, β-naphthol), a potential antinematodal drug, is a widely used intermediate for the production of dyes and other compounds.
either of two isomeric hydroxyl derivatives, C10H7OH, of naphthalene (alpha-naphthol, or 1-naphthol, and beta-naphthol, or 2-naphthol ), white or yellowish crystals, with a phenolic odor, that darken on exposure to light: used chiefly in dyes, drugs, perfumes, and insecticides.
Description
Beta Naphthol is a colorless crystalline solid.
Beta Naphthol is an isomer of 1-naphthol.
Beta Naphthol is used in making azo dyes, pigments, fluorescent whiteners, tanning agents, antioxidants,antiseptics as an antioxidant for turpentine and rubbers.
The compound 2-naphthol, or Beta naphthol, is regarded as the most important chemical intermediate based on naphthalene.
Beta Naphthol is manufactured by fusing 2-naphthalenesulfonic acid with caustic soda and is converted into numerous dyes and dye intermediates, as well as into tanning agents, antioxidants, and antiseptics. Beta Naphthol has been shown to be carcinogenic.
Beta Naphthol is used in the manufacture of dyes and dyes intermediates and in pharmaceuticals industries.
Beta Naphthol is also the starting material for a whole series of naphthol dye stuffs.
The technology for manufacture of Beta Naphthol was imported by few companies who have installed the plant.
However, the production was inadequate to meet the demand of Beta Naphthol in the country.
Central Fuel Research Institute, Dhanbad has developed the process and the Corporation licensed the process to one firm in Bihar and further funded to the firm for further development/improvement of the process.
Thus, with the assistance of the Corporation the firm has achieved a great commercial success.
About Beta Naphthol
Helpful information
Beta Naphthol is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, at ≥ 10 to < 100 tonnes per annum.
Beta Naphthol is used in formulation or re-packing and at industrial sites.
Consumer Uses
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the routes by which Beta Naphthol is most likely to be released to the environment.
Article service life
ECHA has no public registered data on the routes by which Beta Naphthol is most likely to be released to the environment. ECHA has no public registered data indicating whether or into which articles the substance might have been processed.
Widespread uses by professional workers
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the types of manufacture using Beta Naphthol. ECHA has no public registered data on the routes by which Beta Naphthol is most likely to be released to the environment.
Formulation or re-packing
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the routes by which Beta Naphthol is most likely to be released to the environment.
Uses at industrial sites
Beta Naphthol is used in the following products: pharmaceuticals and laboratory chemicals.
Beta Naphthol has an industrial use resulting in manufacture of another substance (use of intermediates).
Beta Naphthol is used for the manufacture of: chemicals.
Release to the environment of Beta Naphthol can occur from industrial use: as an intermediate step in further manufacturing of another substance (use of intermediates) and for thermoplastic manufacture.
Manufacture
ECHA has no public registered data on the routes by which Beta Naphthol is most likely to be released to the environment.
IUPAC NAMES:
Beta Naphthol
2-naphthol
2-Naphthol
2-naphthol
Beta Naphthol
Beta Napthol
Beta-naphthol
beta-Naphthol
beta-naphthol
Naphtalen-2-ol
naphthalen-2-ol
ß-Naphthol
SYNONYMS:
c.i.37500
c.i.azoiccouplingcomponent1
c.i.developer5
Developer A
Developer AMS
Developer BN
developera
developerams
developerbn
naphthyl hydroxide
Naphthyl alcohol
NAPHTHOL, B-
iso-Napthol
BETA NAPHTHO
2-naphthol (beta)
Beta Naphthol (2-Naphthol)
B-NAPHTOL
BETA NAPHTHOL 99% MIN
2-NAPHTHOL (BETA), FOR ANALYTICAL PURPOS ES
2-NAPHTHOL R. G., REAG. PH. EUR.
2-NAPHTHOL POWDER
2-NAPHTHOL (BETA), FLUORESCENCE INDICATO R
betaNaphthol, Low Naphthalene
2-NaphtholA.R.
2-NaphtholGr
2-NaphtholForSynthesis
BetaNaphthol99%
2-Naphthol, 97+%
β-Monoxynaphthalene
2-Naphthol, 99+%
2-Naphthol, tech., 97%
2-NAPHTHOL,PURIFIED
2-NAPHTHOL,REAGENT
2-HYDROXYNAPTHALENE
NAPHTHOL-2
BETA NAPHTHOL ( 2-HYDROXY NAPHTHALENE)
2-NAPHTHOL, 98+%
2-NAPHTHOL(β-NAPHTHOL)
B-NAPHTHOL WITH GC
Naphth-2-ol
b-NAPHTHOL extrapure AR
2-Naphthol 98%
2-Naftol
2-Naftolo
2-Naphtol
Antioxygene BN
Azogen Developer A
azogendevelopera
azoiccouplingcomponent1
beta-Monoxynaphthalene
beta-Naftol
beta-Naftolo
beta-Naphthyl alcohol
beta-Naphthyl hydroxide
2-Hydroxynaphthalene N-Hydroxy-N-nitrosobenzenamine ammonium salt
beta-naphthylalcohol
beta-naphthylhydroxide
beta-Naphtol
2-NAPHTHOL
naphthalen-2-ol
135-19-3
beta-naphthol
2-Naphthalenol
Betanaphthol
2-Hydroxynaphthalene
Isonaphthol
Developer BN
Naphthol B
2-Naphtol
Azogen developer A
beta-Naphtol
beta-Napthol
Developer A
Developer AMS
beta-Hydroxynaphthalene
2-Naftolo
2-Naftol
Developer sodium
C.I. Developer 5
beta-Naphthyl alcohol
beta-Monoxynaphthalene
beta-Naftol
beta-Naftolo
beta-Naphthyl hydroxide
NAPHTHOL, BETA
.beta.-Naphthol
C.I. Azoic Coupling Component 1
UNII-P2Z71CIK5H
.beta.-Naftolo
.beta.-Naphtol
.beta.-Napthol
.beta.-Naftol
NSC 2044
C.I. 37500
2-Naphthol, 98%
.beta.-Naphthyl alcohol
.beta.-Monoxynaphthalene
.beta.-Hydroxynaphthalene
.beta.-Naphthyl hydroxide
2-Naphthalenol, homopolymer
CHEBI:10432
2-Naphthol, 99+%
DSSTox_CID_7061
DSSTox_RID_78296
DSSTox_GSID_27061
2-Naftol [Dutch]
beta-Naftol [Dutch]
2-Naphtol [French]
Caswell No. 590
2-Naftolo [Italian]
beta-Naphtol [German]
beta-Naftolo [Italian]
2-Napththol
26716-78-9
CAS-135-19-3
Betanaphthol [NF]
HSDB 6812
EINECS 205-182-7
EPA Pesticide Chemical Code 010301
Hydronaphthol
AI3-00081
2-napthol
napthalen-2-ol
2-naphthylalcohol
naphth-2-ol
Naphthol AS-PTR
Naphthol, .beta.
03V
EINECS 215-322-9
2-hydroxy naphthalene
2-Naphthol, Reagent
2-Naphthol, Purified2-Naphthol, 99%
Naphth-2-ol, 10
beta.-hydroxynaphthalene
2-Naphthol, 98.5%
2-Naphthol, LR, >=98%
Naphthalen-2-ol (beta-Naphthol)
Sodium 2-naphthoxide (Salt/Mix)
2-Naphthol, purum, >=98.0% (GC)
2-Naphthol, BioXtra, >=99.0% (GC)
SBI-0207084.P001
2-Naphthol, SAJ first grade, >=98.0%
2-Naphthol, fluorescence indicator, >=99.0%
3-ETHYL-5-METHYLISOXAZOLE-4-CARBOXYLICACID
4-06-00-04208 (Beilstein Handbook Reference
