2-chloro 3,5-dimethyl pyarazine

2-chloro 3,5-dimethyl pyarazine Property

Boiling point:

186.6±35.0℃ (760 Torr)

Density 

1.184±0.06 g/cm3 (20 ºC 760 Torr)

refractive index 

1.5230 to 1.5270

Flash point:

83.1±11.5℃

storage temp. 

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

solubility 

Chloroform, Methanol (Slightly)

pka

0.47±0.10(Predicted)

form 

Oil

color 

Colourless

CAS DataBase Reference

38557-72-1

Safety

Risk Statements 

36/38

Safety Statements 

23-26-36/37/39

RIDADR 

1993

Hazard Note 

Harmful

HazardClass 

3

PackingGroup 

Ⅲ

HS Code 

2933998090

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.

P271Use only outdoors or in a well-ventilated area.

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

2-chloro 3,5-dimethyl pyarazine Chemical Properties,Usage,Production

Uses

2-Chloro-3,5-dimethylpyrazine, is a halogenated pyrazine, that can be used as an intermediates in chemical synthesis.

Synthesis

The general procedure for the synthesis of 2-chloro-3,5-dimethylpyrazine from 2,6-dimethylpyrazine was as follows: first, 7.12 g of 2,6-dimethylpyrazine and 6.5 mL of dimethylformamide (DMF) were added to a three-necked flask fitted with a dropping funnel and a thermometer, and refluxed under nitrogen protection. Subsequently, 6.7 mL of thionyl chloride was added to the dropping funnel and the reaction vessel was cooled in an ice bath. Thionyl chloride was slowly added dropwise while stirring the reaction mixture, controlling the reaction temperature in the range of 45 ± 5 °C. After the dropwise addition was completed, the reaction solution temperature was allowed to drop below 40°C and quenched by slowly adding water. After reconfirming that the temperature of the reaction solution was below 40 °C, aqueous sodium hydroxide was added to adjust the pH to 7-8. Subsequently, the reaction mixture was subjected to hydrodistillation. The distilled aqueous phase was extracted with dichloromethane and the organic layer was separated. The organic layer was dried over anhydrous magnesium sulfate and filtered, the filtrate was distilled to remove the solvent, and the residue was purified by distillation under reduced pressure to afford the target product 2-chloro-3,5-dimethylpyrazine (clear colorless liquid, 36% yield).

References

[1] Patent: WO2013/112788, 2013, A1. Location in patent: Paragraph 00660
[2] Patent: WO2008/149828, 2008, A1. Location in patent: Page/Page column 80-81; 82
[3] European Journal of Organic Chemistry, 2005, # 19, p. 4141 - 4153