Oxidation of N-1 and N-2 alkylbenzotriazoles with m-chloroperbenzoic acid afforded 1-alkylbenzotriazole 3-oxides and 2-alkylbenzotriazole-4,4-diones, respectively. The quinonic compounds inhibited the "in vitro" growth of both HeLa and KB cells, the synthesis of macromolecules (DNA, RNA, and proteins), and the uptake of glucose by Ehrlich carcinoma ascites cells. A possible mode of action is suggested.