Provided are a chemical compound of an isocitrate dehydrogenase inhibitor, and an application thereof, belonging to the field of medicinal chemistry； specifically provided is the chemical compound represented by formula I, or its isomer, pharmaceutically acceptable salt, crystal, solvate, or prodrug, as well as their preparation methods and pharmaceutical compositions containing said chemical compound, and an application of said chemical compound or composition. The chemical compound has very good ability to inhibit mutant IDH2 enzyme activity and to inhibit mutant IDH2 neoplastic cells, and may be used for preventing and/or treating a tumor characterized by the presence of mutant IDH2.本發明屬於醫藥化學領域，涉及一類作為異檸檬酸脫氫酶抑制劑的化合物及其應用，具體地，本發明提供式I所示的化合物或其異構體、藥學上可接受的鹽、結晶、溶劑化物或前藥，它們的製備方法以及含有這些化合物的藥物組合物和這些化合物或組合物的應用。本發明的化合物具有非常好的抑制突變型IDH2酶活性及抑制突變型IDH2腫瘤細胞的功能，可用於預防和/或治療以突變型IDH2的存在為特徵的腫瘤。
