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.