2,5-Dichloropyrazine Chemical Properties

Melting point:

0 °C (approx)

Boiling point:

184.4±35.0 °C(Predicted)

Density 

1.493±0.06 g/cm3(Predicted)

storage temp. 

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

form 

liquid

pka

-4.23±0.10(Predicted)

color 

Colourless

InChI

InChI=1S/C4H2Cl2N2/c5-3-1-7-4(6)2-8-3/h1-2H

InChIKey

JVSDZAGCHKCSGR-UHFFFAOYSA-N

SMILES

C1(Cl)=NC=C(Cl)N=C1

Safety Information

Hazard Codes 

Xn

Risk Statements 

22-41

Safety Statements 

26-39

HS Code 

29339900

2,5-Dichloropyrazine Usage And Synthesis

Application

2,5-Dichloropyrazine is a pharmaceutical intermediate that can be obtained by first chlorinating pyrazin-2-amine to obtain 5-chloropyrazin-2-amine, and then by diazotization to obtain 2,5-dichloropyrazine.

Chemical Properties

Colorless liquid

Synthesis

Step 2: Synthesis of 2,5-dichloropyrazine To a stirred solution of 5-chloropyrazin-2-amine (1 g, 7.751 mmol) in concentrated hydrochloric acid (10 mL), an aqueous solution of sodium nitrite (1.1 g, 15.89 mmol) was slowly added at -10 °C, and the addition process lasted for 1 hour. After addition, the reaction mixture was stirred at 0 °C for 1 h, and then brought to room temperature and continued stirring for 2 h. The reaction was carried out by thin layer chromatography (TLC). The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the reaction mixture was neutralized with 50% sodium hydroxide (NaOH) solution and subsequently extracted with dichloromethane (DCM). The organic layers were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by column chromatography on silica gel (100-200 mesh) to afford 2,5-dichloropyrazine (0.59 g, 15% yield) as a colorless oil using hexane solution containing 2% ethyl acetate as eluent. Mass spectrum (MS): 184.1 [M-1].

References

[1] Patent: US2017/291910, 2017, A1. Location in patent: Paragraph 0565-0567
[2] Patent: WO2008/85316, 2008, A1. Location in patent: Page/Page column 53-54
[3] Patent: WO2005/97778, 2005, A1. Location in patent: Page/Page column 15
[4] Patent: WO2004/56369, 2004, A1. Location in patent: Page/Page column 24
[5] Patent: WO2005/123723, 2005, A1. Location in patent: Page/Page column 11-12

2,5-Dichloropyrazine(19745-07-4)Related Product Information

• Sulfachoropyrazine sodium
• 2,3-Dichloropyrazine,98%,2,3-DICHLOROPYRAZINE
• Pyrazinamide
• Glipizide
• 2,6-Dichloropyrazine,99%,2,6-DICHLOROPYRAZINE
• 3,5-Dichloropyrazine-2-carboxylic acid
• METHYL 3-AMINO-5,6-DICHLOROPYRAZINE-2-CARBOXYLATE,3-Amino-5,6-Dichloropyrazine-2-Carboxylic Acid Methyl Ester
• 2-AMINO-3,5-DICHLOROPYRAZINE
• 2-Dichloropyrazin
• 3,5-dichloropyrazine-2-carbaldehyde
• METHYL 3,5-DICHLOROPYRAZINE-2-CARBOXYLATE
• 3,5-Dichloropyrazine-2-carboxyamide
• 3,5,6-TRICHLORO-N-METHYLPYRAZIN-2-AMINE
• METHYL 3,6-DICHLOROPYRAZINE-2-CARBOXYLATE
• 2,5-Dichloropyrazine
• 2,5-DICHLORO-3,6-DIPHENYL PYRAZINE
• 2,5-DICHLORO-3,6-DIMETHYLPYRAZINE
• 3,5-DICHLOROPYRAZINE-2-CARBOXAMIDE