4-Nitrobenzoic acid-d4 is the deuterium labeled 4-Nitrobenzoic acid (HY-Y0607). 4-Nitrobenzoic acid is a nitroaromatic compound that can be used in the synthesis of other active compounds. 4-Nitrobenzoic acid is also an inhibitor agent, which can be used for the recognition of the Mycobacterium tuberculosis complex and differentiation from non-tuberculous mycobacteria[1].