•We realized potassium bromide, a green and highly efficient catalyst, to catalyze the formation of the desired NS bond.•The reaction proceeded in an excellent yield.•High functional group tolerance is exhibited in this reaction as well.•The products are obtained in excellent yields even in gram scale.•The products exhibit promising applications in industry.N-Substituted benzo[d]isothiazol-3(2H)-ones are a family of compounds with extremely important application. Recently, we have developed a new green pathway to synthesize these compounds via potassium bromide-catalyzed intramolecular oxidative dehydrogenative cyclization. This reaction has high functional group tolerance and affords excellent yield even in gram scale.Download high-res image (65KB)Download full-size image

•4-Chloro-N-(2-(2-nitrophenyl)acetoxy)-N-phenylbenzamide was synthesized.•Its structure was characterized by NMR, MS, IR, X-ray and cyclic voltammetry.•Some molecular properties were calculated by density functional theory calculations.•Antitumor potencies were evaluated in vitro.4-Chloro-N-(2-(2-nitrophenyl)acetoxy)-N-phenylbenzamide was synthesized and characterized by 1H NMR, 13C NMR, MS, IR and X-ray diffraction methods. The structure–property relationship and the antitumor activity based on electrochemical measurements, density functional theory calculations (DFT) and methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay were investigated. The crystal structure adopts monoclinic space group P21/n with the unit cell parameters of a = 12.4385(10) Å, b = 6.5036(5) Å, c = 24.7944(19) Å, β = 103.045(9)°, V = 1954.0(3) Å3, Z = 4, and stabilized by π–π conjugation and hydrogen bonding interactions. The observed results of the compound have been compared with theoretical results and it is found that the experimental data show good agreement with calculated values. And the compound had slightly better inhibition than suberoylanilide hydroxamic acid (SAHA) in NCI-H460 cell line as well as the nearly same as SAHA in MCF-7, HCT-116, PC-3, and A549 cell lines.Graphical abstract