4-Azabenzimidazole Chemical Properties

Melting point:

148-151 °C (lit.)

Boiling point:

140-150°C/0.1mm

Density 

1.2058 (rough estimate)

refractive index 

1.5589 (estimate)

Flash point:

140-150°C/0.1mm

storage temp. 

Inert atmosphere,Room Temperature

solubility 

Soluble in dimethylformamide.

form 

powder

pka

8.46±0.20(Predicted)

Appearance

Off-white to light brown Solid

BRN 

2600

CAS DataBase Reference

273-21-2(CAS DataBase Reference)

EPA Substance Registry System

1H-Imidazo[4,5-b]pyridine (273-21-2)

Safety Information

Hazard Codes 

Xn

Risk Statements 

22

Safety Statements 

24/25

WGK Germany 

3

RTECS 

NJ5108000

HS Code 

2933998090

Toxicity

mouse,LD50,intraperitoneal,> 200mg/kg (200mg/kg),Journal of Medicinal Chemistry. Vol. 6, Pg. 480, 1963.

MSDS

• Language:English Provider:1H-Imidazo[4,5-b]pyridine
• Language:English Provider:ACROS
• Language:English Provider:SigmaAldrich
• Language:English Provider:ALFA

4-Azabenzimidazole Usage And Synthesis

Chemical Properties

yellow to light brown powder

Uses

4-Azabenzimidazole is used in the preparation of imidazo[4,5-b]pyridine 4-oxide. It is also used as a reagent to prepare benzoylmethyl-substituted azoles which are inhibitors of nitric oxide synthase with antioxidant properties.

Definition

ChEBI: The [4,5-b]-fused isomer of imidazopyridine.

Synthesis

The general procedure for the synthesis of 4-azabenzimidazole from 2,3-diaminopyridine and triethyl orthoformate was as follows: to evaluate the catalytic performance of different γ-Fe2O3@SiO2-HA catalysts, a catalytic amount of γ-Fe2O3@SiO2-HA (2.5 mol%) was added to a glass flask containing 1.2 mmol of triethyl orthoformate and stirred at room temperature for 15 minutes. Subsequently, 2 mmol of 2,3-diaminopyridine was added to the reaction mixture and the reaction was continued until a predetermined time was reached. The progress of the reaction was monitored by thin layer chromatography (TLC) and the unfolding agent was a solvent mixture of hexane and ethyl acetate (ratio 4:1 or 7:3 for diamines). Upon completion of the reaction, 5 mL of dichloromethane (ethyl acetate was used for entries 8 and 9) was added to the mixture, followed by separation of the catalyst by an external magnet for subsequent use. Finally, the resulting solution was concentrated on a rotary evaporator to give the purified 4-azabenzimidazole solid product.

References

[1] Asian Journal of Chemistry, 2013, vol. 25, # 6, p. 3446 - 3448
[2] Journal of Molecular Structure, 2012, vol. 1027, p. 156 - 161

4-Azabenzimidazole(273-21-2)Related Product Information

• 2-Methylbenzimidazole
• Methimazole
• Benzimidazole
• Levamisole
• Mebendazole
• 2-Chlorobenzimidazole
• Pyridine
• 6-BROMO-2-METHYL-4H-IMIDAZO[4,5-B]PYRIDINE
• 4-AZABENZIMIDAZOLE, 99
• 5-AZABENZIMIDAZOLE
• 1H-IMIDAZO[4,5-B]PYRIDINE-2-THIOL
• 4,5,6,7-Tetrabromo-2-azabenzimidazole, 4,5,6,7-Tetrabromobenzotriazole, NSC 231634, TBBt,4,5,6,7-TETRABROMO-2-AZABENZIMIDAZOLE
• benzimidazolone
• 4-Azabenzimidazole
• Alkyl benzimidazole
• IMIDAZOPYRIDINE
• 2-(4-CHLOROPHENYL)-1-([3-(TRIFLUOROMETHYL)BENZYL]OXY)-1H-IMIDAZO[4,5-B]PYRIDINE
• 1-[(4-CHLOROBENZYL)OXY]-2-PHENYL-1H-IMIDAZO[4,5-B]PYRIDINE