5-Hydroxyquinoline

5-Hydroxyquinoline Property

Melting point:

223-226 °C(lit.)

Boiling point:

264.27°C (rough estimate)

Density 

1.1555 (rough estimate)

refractive index 

1.4500 (estimate)

storage temp. 

Keep in dark place,Inert atmosphere,Room temperature

solubility 

DMSO, Methanol

form 

Solution

pka

pK1:5.20(＋1);pK2:8.54(0) (20°C)

color 

Colorless to yellow, may darken during storage

Water Solubility 

416.5mg/L(20 ºC)

BRN 

114514

InChI

InChI=1S/C9H7NO/c11-9-5-1-4-8-7(9)3-2-6-10-8/h1-6,11H

InChIKey

GYESAYHWISMZOK-UHFFFAOYSA-N

SMILES

N1C2C(=C(O)C=CC=2)C=CC=1

CAS DataBase Reference

578-67-6(CAS DataBase Reference)

NIST Chemistry Reference

5-Quinolinol(578-67-6)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36

WGK Germany 

3

RTECS 

VC4100000

Hazard Note 

Irritant

HS Code 

29334900

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P271Use only outdoors or in a well-ventilated area.

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

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.

5-Hydroxyquinoline Chemical Properties,Usage,Production

Chemical Properties

White to beige crystalline powder

Uses

5-Quinolinol (5-Hydroxyquinoline) was used as an internal standard in the reaction to measure morphine concentration in serum or plasma. It was also used as a lipophilic chelator and it decreased the rate of deoxygenation.

Definition

ChEBI: Quinolin-5-ol is a monohydroxyquinoline.

Synthesis

General procedure for the synthesis of 5-hydroxyquinoline from 5-aminoquinoline: to a stirred aqueous solution (100 mL) of 5-aminoquinoline (5.0 g, 34.67 mmol) was added sodium bisulfite (NaHSO3; 25.2 g, 242.1 mmol). The mixture was heated to reflux temperature and stirred for 36 hours at room temperature. After completion of the reaction, the solution was cooled to room temperature, sodium hydroxide (NaOH; 9.7 g, 242.5 mmol) was added and the mixture was continued to be stirred at reflux temperature for 8 hours. The progress of the reaction was monitored by thin layer chromatography (TLC). At the end of the reaction, the mixture was cooled to room temperature and the pH was adjusted to 7.0 with 6 equivalents (N) hydrochloric acid (HCl). the precipitate was collected by filtration, washed with water and dried under high vacuum to afford the target product, 5-hydroxyquinoline (3.2 g, 22.04 mmol, 64% yield) as a light yellow solid.1H NMR (500 MHz, CDCl3): δ 8.92 (s 1H), 8.58 (d, J = 8.5 Hz, 1H), 7.71 (d, J = 8.5 Hz, 1H), 7.53 (t, J = 8.0 Hz, 1H), 7.41 (dd, J = 8.5, 4.5 Hz, 1H), 6.88 (d, J = 7.5 Hz, 1H), 6.10 (br s, 1H). Mass spectrum (ESI): m/z 146 [M + H]+.

References

[1] Patent: US2012/329802, 2012, A1. Location in patent: Page/Page column 25-26
[2] Bioorganic and Medicinal Chemistry Letters, 2016, vol. 26, # 14, p. 3307 - 3312
[3] Patent: KR101778938, 2017, B1. Location in patent: Paragraph 0147-0148; 0155; 0160-0162
[4] Journal fuer Praktische Chemie (Leipzig), 1893, vol. <2> 47, p. 431
[5] Journal of the American Chemical Society, 1946, vol. 68, p. 1562