Nitriles in organic synthesis: synthesis of some new Polyfunctionally substituted pyrazines and pyrazine derivatives

ABSTRACT

It has been found that alpha-tosyloximinomalononitrile [Ib] reacted with benzoylacetonitrile to yield the pyridinium salt II. Compound II reacted with hydrazine hydrate and hydroxylamine hydrochloride to give VII and VIII, respectively. On the other hand, compound II undergoes cyclization by boiling in acetic acid/hydrochloric acid mixture to give VI. When Ib reacted with cyanoacetamide and pyridine it yielded the pyridinium salt III which on reacting with hydrazine hydrate, hydroxylamine hydrochloride and thiourea yielded X, XI and XII, respectively. III also undergoes cyclization by boiling in acetic acid/hydrochloric acid mixture to yield the pyrazine derivative V. Compound Ib reacted with cyanoacetamide by boiling in pyridine to give IV