98-97-5, name is Pyrazine-2-carboxylic acid, belongs to pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. Formula: C5H4N2O2
Step A. Preparation o f Pyrazine-2-carbonyl chloride. A 500 ml three neck round bottomed flask equipped with a stir bar, thermocouple, heating mantle with digital temperature controller, condenser and nitrogen inlet/outlet was charged with 15 g (0.12 mol) of pyrazine carboxylic acid, 225 mL of toluene (Kf < 0.02wt%) and 26.4 ml (43 g, 0.36 mol) of thionyl chloride. The thin slurry was heated to 75 C and stirred overnight (10-16 hr). After cooling the reaction mixture to room temperature the solvent and excess thionyl chloride were removed in vacuo as follows: Reaction mixture was stripped under full vacuum at 60 C (bath temperature) to approximately 1/3 its original volume and then (175 ml) of fresh toluene was added. Concentration was continued, again stripping to 1/3 original volume followed by re-dilution with 225 ml of fresh toluene to provide the pyrazine acid chloride in a toluene solution.
The synthetic route of 98-97-5 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; CEPHALON, INC.; ROEMMELE, Renee Caroline; WO2011/87822; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem