Piperazine is an organic compound consisting of a six-membered ring containing two nitrogen atoms in opposite positions in the ring. The chemical formula of piperazine is C4H10N2, and it is an important pharmaceutical intermediate. Pyrimidines and piperazines are known to be the backbone of many bulk compounds and important core structures for approved drugs; studies have shown that combining a pyridine ring with a piperazine moiety within a single structural framework enhances biological activity.
Naphthyridine is a class of aromatic heterocyclic compounds whose chemical formula is C8H6N2. They consist of naphthalene bicyclic rings in which two carbon atoms are replaced by nitrogen atoms. There are ten isomers of naphthyridine, because naphthyridine has two benzene rings, has strong π-π conjugation, and has better luminescence properties. Common naphthyridines are 1,8-naphthyridines. There are many kinds of 1,8-naphthyridine derivatives, and they are widely used.