Background: Compounds having N-heterocyclic moieties are of huge importance in the
field of agrochemical, pharmaceutical, biological, fragrances, etc. Due to a lot of applications associated
with pyrazine moieties, their synthesis has always been important for organic chemists.
Method: Surfeit synthetic methodologies are documented in literature. Most of the methodologies used
expensive solvents, harmful metal catalyst and all suffer from rigorous work-up procedures. An efficient,
environmentally benign methodology, needs to be developed. We mixed ethylenediamine
(2mmol) with 1,2-diketone(1mmol), later, α-hydroxy ketone and α-bromo ketone on magnetic stirrer at
room temperature under neat reaction condition for 5 to 10 hrs.
Results: After purification by column chromatography using silica gel(60-120 mesh) and pet-ether, ethylacetate
mixture as eluent, we achieved pyrazine derivatives from moderate to high yield.
Conclusion: Efficient and clean procedure for one-pot preparation of pyrazines from ethylenediamine
and 1,2-diketones or with α-hydroxy ketone or with α-bromo ketone has been carried out under neat reaction
condition at room temperature. Environmentally benign process furnishing moderate to excellent
yields of the product and simple work-up giving pure products are special features of this reaction.