4-Methyl-3-[[4-(3-pyridinyl)-2-pyrimidinyl]amino]benzoic acid is used in the preparation of (pyridinyl)-N-[(triazolyl)phenyl]pyrimidinamine derivatives and (pyridinyl)-N-[oxadiazolyl)phenyl]pyrimidinamine derivatives, and can be used in the detection of their activity as antileukemia agents (neoplastic stem cell leukemia). 4-Methyl-3-[[4-(3-pyridinyl)-2-pyrimidinyl]amino]benzoic acid is also a Nilotinib (N465300) intermediate, which might be useful in treatment of chronic myelogenous leukemia.