MtTMPK-IN-9 (compound 28) is a moderate M. tuberculosis thymidylate kinase ( Mtb TMPK) inhibitor with an IC 50 value of 48 μM. MtTMPK-IN-9 has sub-micromolar activity against mycobacteria (MICs = 6.25~9.4 μM) without significant cytotoxicity. MtTMPK-IN-9 can be used for researching tuberculosis.