Study On The Synthesis Of Pyrazine Derivatives Based On Alkenyl Azide

Vinyl azides are important organic synthons that provide a variety of N-heterocycles and other functional groups.?-substituted vinyl azides are a special class with unique reactivity that not only acts as an azide but also as a free radical acceptor,an enamine-type nucleophile,and even an electrophile.A wide range of N-containing compounds and their derivatives are available.Alkenyl azides can produce a series of important intermediates,such as iminodiazepine ions,nitrosonium ions,imino radicals and metal enamine groups.These intermediates are used in the cycloaddition,C-H functionalization,hydrolysis process and series reaction under transition metal/photooxidation catalysis.The synthesis and application of heterocyclic compounds have always been one of the research hotspots and frontier fields of organic synthetic chemistry.Pyrazines are an important class of nitrogen heterocyclic compounds widely found in natural products,drug molecules and bioactive molecules.Typical methods for the preparation of pyrazines include the condensation of o-diamines with o-diones or ?-aminoketones.It has also been developed using different kinds of starting materials such as ?-hydroxyketone,?-haloketone,?-haloenol acetate,nitroepoxide,2H-acridine and the like to synthesize pyrazine.However,most of these methods require multiple steps as well as metal catalysts.Therefore,it is necessary to develop a new method for synthesizing pyrazine from a simple and readily available inexpensive starting material.Here,we use two molecules of alkenyl azide to lose nitrogen coupling in the aqueous phase to form pyrazine.In the conventional reaction,a 2H-acridine intermediate is obtained,and 2H-acridine is dimerized to form a pyrazine,and the reaction directly forms a pyrazine from an alkenyl azide.The reactive functional group has high tolerance and a wide range of substrates.