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.
Benzoisothiazole is a benzo derivative of isothiazole, which is a kind of bicyclic aromatic organic compound, which is formed by fusion of a six-membered benzene ring and a five-membered heterocyclic ring composed of two adjacent heteroatoms, N and S. Benzoisothiazoles are important pharmaceutical intermediates. Some benzoisothiazole derivatives exhibit potent cytotoxic and antitumor activities.
Indolinone derivatives have in common the presence of a hydrogen bond between the C-2 carbonyl and a hydrogen donor in a side chain, generally a pyrrole ring. Indolinone displays very promising antitumor properties by inhibiting various kinase families.