2-naphthol

Structural formula
General
Surname	2-naphthol
other names	β-naphthol; 2-hydroxynaphthalene; Naphth-2-ol;
Molecular formula	C 10 H 8 O
Brief description	white crystalline powder with a phenolic odor
External identifiers / databases
EC number	205-182-7
ECHA InfoCard	100.004.712
PubChem	8663
Wikidata	Q949232
properties
Molar mass	144.17 g mol −1
Physical state	firmly
density	1.22 g cm −3
Melting point	123 ° C
boiling point	285 ° C
pK s value	9.57 (25 ° C)
solubility	sparingly soluble in water: 1 g l −1 (20 ° C)
safety instructions
H and P phrases	H: 302 + 332-400
	P: 273
Toxicological data	1960 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

2-naphthol (also β-naphthol ) is an organic chemical compound. The structure consists of a naphthalene structure with an attached hydroxyl group (-OH). It can therefore also be called 2-hydroxynaphthalene. There is another isomer , 1-naphthol (α-naphthol, 1-hydroxynaphthalene).

presentation

2-naphthol

The compound can be obtained by alkaline hydrolysis of sodium naphthalene-2-sulfonate, by oxidation of naphthalene or from 2-bromonaphthalene and tert-butyl hydroperoxide .

properties

2-Naphthol is a crystalline solid that melts at 123 ° C. According to Antoine, the vapor pressure function of the melt results from log ₁₀ (P) = A− (B / (T + C)) (P in kPa, T in K) with A = 3.058, B = 467.4 and C = −257 , 6 in the temperature range from 130 ° C to 160 ° C.

Derivatives

2-Napththol can be converted, for example, with methanol or with ethanol to form the methyl or ethyl ether, 2-methoxynaphthalene or 2-ethoxynaphthalene . These ethers are used as artificial fragrances .

Some Sudan dyes are derived from 2-naphthol, such as Sudan I , Sudan II , Sudan III , Sudan IV , Sudan Red B and Sudan red G .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on 2-naphthol in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
↑ Zvi Rappoport (Ed.): CRC Handbook of Tables for Organic Compound Identification . 3 ^rd Edition, CRC Press / Taylor and Francis, Boca Raton, FL, 1967, ISBN 0-8493-0303-6 , Acid Dissociation Constants of Phenols in Aqueous Solution, S. 434th
↑ Entry on 2-naphthol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Toxicological assessment of 2-naphthol (PDF) at the professional association raw materials and chemical industry (BG RCI), accessed on August 20, 2012.
^ Gerhard Wendt, B. Vithal Shetty, William F. Bruce: Mercurial Diuretics. I. Addition of Mercuric Chloride and Secondary Amines to Allylamides. In: Journal of the American Chemical Society. 81, 1959, p. 4233, doi : 10.1021 / ja01525a029 .
↑ F. Barontini, V. Cozzani: thermogravimetric as a screening tool for the estimation of the vapor pressure of pure compounds. In: J. Therm. Anal. Calorim. 89, 2007, pp. 309-314.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on 2-naphthol in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .

[CRCO-2] Zvi Rappoport (Ed.): CRC Handbook of Tables for Organic Compound Identification . 3 ^rd Edition, CRC Press / Taylor and Francis, Boca Raton, FL, 1967, ISBN 0-8493-0303-6 , Acid Dissociation Constants of Phenols in Aqueous Solution, S. 434th

[CLP_100.004.712-3] Entry on 2-naphthol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[bg-4] Toxicological assessment of 2-naphthol (PDF) at the professional association raw materials and chemical industry (BG RCI), accessed on August 20, 2012.

[DOI10.1021/ja01525a029-5] Gerhard Wendt, B. Vithal Shetty, William F. Bruce: Mercurial Diuretics. I. Addition of Mercuric Chloride and Secondary Amines to Allylamides. In: Journal of the American Chemical Society. 81, 1959, p. 4233, doi : 10.1021 / ja01525a029 .

[6] F. Barontini, V. Cozzani: thermogravimetric as a screening tool for the estimation of the vapor pressure of pure compounds. In: J. Therm. Anal. Calorim. 89, 2007, pp. 309-314.