The invention is directed to a compound of formula (I) or a pharmaceutically acceptable salt thereof, wherein R1-R6 are defined herein. The invention is also directed to compositions containing a compound of formula (I) and to the use of such compounds in the inhibition of mutant IDH proteins having a neomorphic activity. The invention is further directed to the use of a compound of formual (I) in the treatment of diseases or disorders associated with such mutant IDH proteins including, but not limited to, cell-proliferation disorders, such as cancer.本發明係關於一種式(I)化合物或其醫藥學上可接受之鹽,其中R1-R6係如本文中所定義。本發明亦關於含有式(I)化合物之組合物,及該等化合物用於抑制具有新變體(neomorphic)活性之突變IDH蛋白的用途。本發明進一步關於式(I)化合物用於治療與該等突變IDH蛋白相關之疾病或病症(包括(但不限於)細胞增殖病症,諸如癌症)的用途。