2.1 Chemical Synthesis
The most prominent route for traditional pyrazine synthesis is the reaction of 1,2-diketones in the presence of ammonia to form diamines or aminoketones [22]. The list of examples is long, nevertheless an easy high yielding representative example is the reaction of diketones with diamines in methanol at room temperature under dry conditions in the presence of tert -BuOK in up to 5 hours, that yields above 70 % of alkylated pyrazines [23].