8-Hydroxyquinoline Property

Melting point:

70-73 °C(lit.)

Boiling point:

267 °C752 mm Hg(lit.)

Density 

1.0340

vapor pressure 

0.221Pa at 25℃

refractive index 

1.4500 (estimate)

Flash point:

267°C

storage temp. 

Store below +30°C.

solubility 

0.56g/l

form 

Liquid

pka

5.017(at 20℃)

color 

White to pale yellow or light beige

Water Solubility 

INSOLUBLE

Sensitive 

Light Sensitive

Merck 

14,4843

BRN 

114512

InChIKey

MCJGNVYPOGVAJF-UHFFFAOYSA-N

LogP

1.85 at 25℃

CAS DataBase Reference

148-24-3(CAS DataBase Reference)

NIST Chemistry Reference

8-Quinolinol(148-24-3)

IARC

3 (Vol. 13, Sup 7) 1987

EPA Substance Registry System

8-Quinolinol (148-24-3)

Safety

Hazard Codes 

Xn,Xi

Risk Statements 

22-68-36/37/38

Safety Statements 

45-36/37/39-26-36

RIDADR 

2811

WGK Germany 

3

RTECS 

VC4200000

Hazard Note 

Harmful/Irritant

TSCA 

Yes

HazardClass 

9

PackingGroup 

III

HS Code 

29334990

Hazardous Substances Data

148-24-3(Hazardous Substances Data)

Toxicity

An LD50 value of 1,200mg/kg was reported for oral administration of 8-hydroxyquinoline to rats (straidsex unspecified; AAPCO, 1966);a value of 48 mg/kg was reported for intraperitoneal administration to mice (strain/sex unspecxed; Bernstein et al., 1963).

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H301Toxic if swalloed

H317May cause an allergic skin reaction

H318Causes serious eye damage

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P202Do not handle until all safety precautions have been read and understood.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

8-Hydroxyquinoline Chemical Properties,Usage,Production

Chemical Properties

8-Hydroxyquinoline is a white to cream-colored crystal or crystalline powder that is insoluble in water or ether and freely soluble in ethanol, acetone, chloroform, benzene, and aqueous mineral acids. It readily forms stable metal chelates, which are soluble or precipitable in organic solvents, depending on the pH of the solution (Hollingshead, 1954).

Originator

Chinosol,Chinosolfabrik

Uses

8-Hydroxyquinoline has a wide variety of uses. Primarily because of their metal chelating properties, 8-hydroxyquinoline and its salts, halogenated derivatives, and metal complexes have been used as analytical reagents (Hollingshead, 1954) and as antimicrobial agents in medicine, fungicides, and insecticides (Harvey, 1975). It is also used as a preservative in cosmetics and tobacco, a chemical intermediate in dye synthesis (IARC, 1977), and a precipitating reagent for uranium and other radioactive metals in nuclear power plant liquid waste effluent. It is used in nuclear medicine with indium-111 (Davis et al., 1978).

Definition

ChEBI: 8-Hydroxyquinoline is a monohydroxyquinoline that is quinoline substituted by a hydroxy group at position 8. Its fungicidal properties are used for the control of grey mould on vines and tomatoes. It has a role as an antibacterial agent, an iron chelator, an antiseptic drug and an antifungal agrochemical. It derives from a hydride of a quinoline.

Application

8-Hydroxyquinoline may be used as a chelating ligand in the preparation of tris-(8-hydroxyquinoline)aluminum (Alq3), an organic electroluminescent compound used in organic light-emitting devices (OLEDs).

Preparation

8-Hydroxyquinoline is synthesized from o-aminophenol by cyclization reaction. Add glycerin into the acid-resistant reaction pot, slowly add concentrated sulfuric acid under stirring, and simultaneously add o-aminophenol and o-nitrophenol in sequence, and add 65% of the total oleum first. Heat up to 125°C, stop heating, naturally heat up to 140°C, and wait until the temperature returns to 136°C. The rest of the oleum was continued to be added, maintaining the temperature at 137°C. After adding acid, keep warm for 4 hours, cool to below 100°C, pump into an acid-resistant pot containing 10 times the amount of water (calculated by o-aminophenol), stir, heat to 75-80°C, use 30% sodium hydroxide The solution was neutralized to pH 7-7.2. The precipitate is released while hot, cooled into a block, and sublimed under reduced pressure to obtain the finished product of 8-hydroxyquinoline.

brand name

Aci-jel;Benzease;Chinosol;Cp-cap;Dermacid;Dermoplast;Fennosan h 30;Heriat;Hydroxybenoxopyridine;Medicone derma-hc;Oxykin;Oxyquinoline-rhp;Pedivol;Phenopyridine;Preconsol;Quinoderm;Quinoped;Quinophenol;Recta medicone-hc;Semori;Serohinol;Serorhinol;Superol;Trimo-san;Triva douch powder;Triva jel.

Therapeutic Function

Antiseptic

World Health Organization (WHO)

Halogenated hydroxyquinoline is structurally related to clioquinol. See WHO comment for clioquinol. (Reference: (WHODI) WHO Drug Information, 77.1, 9, 1977)

General Description

White to off-white or faintly yellow crystalline powder. Phenolic odor.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

8-Hydroxyquinoline darkens on exposure to light. 8-Hydroxyquinoline readily forms stable metal chelates. 8-Hydroxyquinoline is incompatible with strong oxidizers. 8-Hydroxyquinoline is also incompatible with many metal ions.

Hazard

Toxic by ingestion. Questionable carcinogen.

Biochem/physiol Actions

8-Hydroxyquinoline is a RNA synthesis inhibitor that acts as a fungicide against Trichophyton mentagrophytes, Myrothecium verrucaria, and Trichoderma viride. The antifungal mechanism of action is not clear but appears to be structurally related.

Clinical Use

8-Hydroxyquinoline (8HQ) is an intermediate of halogenated quinoline anti-amebic drugs, including quiniodoform, clioquinoline, diiodoquinoline and the like. These drugs exert anti-amebic effects by inhibiting intestinal commensal bacteria, and are effective against amoebic dysentery, but have no effect on extra-intestinal amoebic parasites.8HQ is a small planar molecule with a lipophilic effect and a metal chelating ability. As a result, 8HQ and its derivatives hold medicinal properties such as antineurodegenerative, anticancer, antioxidant, antimicrobial, anti-inflammatory, and antidiabetic activities.

Safety Profile

8-Hydroxyquinoline (8-HQ) may be a skin irritant in man. Hair depigmentation was seen in mice treated dermally. Dilute solutions were slightly irritating to the eyes of rabbits. In cases of human poisoning (by ingestion or by the administration of an enema containing 8-HQ or its sulphate), the kidney, liver and blood were the principal sites of toxic attack. Comprehensive studies involving repeated oral administration of 8-HQ to rodents failed to identify any particular sites for toxic attack and provided no convincing evidence of carcinogenicity. 8-HQ induced chromosomal damage in mammalian cells in culture (including human cells), but gave conflicting results in mice treated intraperitoneally. Both 8-HQ and its sulphate have induced mutagenicity in Ames bacterial tests and there was some evidence of mutagenic activity in mammalian cells treated in culture.

Purification Methods

Crystallise oxine from hot EtOH, acetone, pet ether (b 60-80o) or water. Crude oxine can be purified by precipitation of copper oxinate, followed by liberation of free oxine with H2S or by steam distillation after acidification with H2SO4. Store it in the dark. It forms complexes with many metals. [Manske et al. Can J Research 27F 359 1949, Phillips Chem Rev 56 271 1956, Beilstein 21 III/IV 1135, 21/3 V 252.]