5-BROMOIMIDAZO[1,2-A]PYRIDINE-2-CARBALDEHYDE

5-BROMOIMIDAZO[1,2-A]PYRIDINE-2-CARBALDEHYDE Property

Density 

1.73±0.1 g/cm3(Predicted)

storage temp. 

under inert gas (nitrogen or Argon) at 2-8°C

pka

1.70±0.50(Predicted)

Appearance

Off-white to light yellow Solid

Safety

HS Code 

2933998090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

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

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

5-BROMOIMIDAZO[1,2-A]PYRIDINE-2-CARBALDEHYDE Chemical Properties,Usage,Production

Synthesis

General procedure: 2-amino-6-bromopyridine (3.0 kg, 17.3 mol) and dimethoxyethane (12 L) were added to the reactor under nitrogen protection and mixed with stirring. Subsequently, 1,1,3-trichloroacetone (5.6 kg, 30.3 mol) was added to the reaction solution at 25 °C in a single addition. The reaction system was slowly warmed to 65 °C (jacket temperature) and maintained at this temperature for 2 to 4 hours until the reaction was confirmed complete by TLC or HPLC monitoring. Upon completion of the reaction, the system was cooled to 10 °C, maintained for 1 h and filtered. The solid product was washed with dimethoxyethane (6 L). The solid was repositioned in the reactor, dimethoxyethane (12 L) and 2N hydrochloric acid (12 L) were added, and the reaction was warmed to 75 °C for 16 to 20 hours or until the reaction was complete. The reaction solution was cooled to 10 °C and the pH was adjusted to 8 with 3N sodium hydroxide solution. the solid product was collected by filtration and washed with water. Finally, the solid was dried at 50 °C for 16 h to give 5-bromoimidazo[1,2-a]pyridine-2-carbaldehyde (2.81 kg, 72% yield). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-D6): δ 10.05 (s, 1H), 8.66 (s, 1H), 7.72 (s, 1H), 7.42 (s, 1H), 7.35 (s, 1H).

References

[1] Organic Process Research and Development, 2009, vol. 13, # 4, p. 781 - 785
[2] Patent: WO2007/87549, 2007, A2. Location in patent: Page/Page column 49
[3] Patent: WO2007/87549, 2007, A2. Location in patent: Page/Page column 39-40